Another Viennese physician of the 18th century, Franz Anton Mesmer, believed that illness was caused by an imbalance of magnetic fluids in the body. He believed he could restore the balance by passing his hands across the patient”s body and waving a magnetic wand over the infected area. Mesmer claimed that his patients would fall into a trance and awaken from it feeling better. The medical community, however, soundly rejected the claim. Today, Mesmer”s technique, known as mesmerism, is regarded as an early forerunner of modern hypnosis.
Modern psychology is deeply rooted in the older disciplines of philosophy and physiology. But the official birth of psychology is often traced to 1879, at the University of Leipzig, in Leipzig, Germany. There, physiologist Wilhelm Wundt established the first laboratory dedicated to the scientific study of the mind. Wundt”s laboratory soon attracted leading scientists and students from Europe and the United States. Among these were James McKeen Cattell, one of the first psychologists to study individual differences through the administration of “mental tests,” Emil Kraepelin, a German psychiatrist who postulated a physical cause for mental illnesses and in 1883 published the first classification system for mental disorders; and Hugo Münsterberg, the first to apply psychology to industry and the law. Wundt was extraordinarily productive over the course of his career. He supervised a total of 186 doctoral dissertations, taught thousands of students, founded the first scholarly psychological journal, and published innumerable scientific studies. His goal, which he stated in the preface of a book he wrote, was “to mark out a new domain of science.”
Compared to the philosophers who preceded him, Wundt”s approach to the study of mind was based on systematic and rigorous observation. His primary method of research was introspection. This technique involved training people to concentrate and report on their conscious experiences as they reacted to visual displays and other stimuli. In his laboratory, Wundt systematically studied topics such as attention span, reaction time, vision, emotion, and time perception. By recruiting people to serve as subjects, varying the conditions of their experience, and then rigorously repeating all observations, Wundt laid the foundation for the modern psychology experiment.
In the United States, Harvard University professor William James observed the emergence of psychology with great interest. Although trained in physiology and medicine, James was fascinated by psychology and philosophy. In 1875 he offered his first course in psychology. In 1890 James published a two-volume book entitled Principles of Psychology. It immediately became the leading psychology text in the United States, and it brought James a worldwide reputation as a man of great ideas and inspiration. In 28 chapters, James wrote about the stream of consciousness, the formation of habits, individuality, the link between mind and body, emotions, the self, and other topics that inspired generations of psychologists. Today, historians consider James the founder of American psychology.
James's students also made lasting contributions to the field. In 1883 G. Stanley Hall (who also studied with Wundt) established the first true American psychology laboratory in the United States at Johns Hopkins University, and in 1892 he founded and became the first president of the American Psychological Association. Mary Whiton Calkins created an important technique for studying memory and conducted one of the first studies of dreams. In 1905 she was elected the first female president of the American Psychological Association. Edward Lee Thorndike conducted some of the first experiments on animal learning and wrote a pioneering textbook on educational psychology.
During the first decades of psychology, two main schools of thought dominated the field: structuralism and functionalism. Structuralism was a system of psychology developed by Edward Bradford Titchener, an American psychologist who studied under Wilhelm Wundt. Structuralists believed that the task of psychology is to identify the basic elements of consciousness in much the same way that physicists break down the basic particles of matter. For example, Titchener identified four elements in the sensation of taste: sweet, sour, salty, and bitter. The main method of investigation in structuralism was introspection. The influence of structuralism in psychology faded after Titchener's death in 1927.
In contradiction to the Structuralists movement, William James promoted a school of thought known as functionalism, the belief that the real task of psychology is to investigate the function, or purpose, of consciousness rather than its structure. James was highly influenced by Darwin”s evolutionary theory that all characteristics of a species must serve some adaptive purpose. Functionalism enjoyed widespread appeal in the United States. Its three main leaders were James Rowland Angell, a student of James; John Dewey, who was also one of the foremost American philosophers and educators; and Harvey A. Carr, a psychologist at the University of Chicago.
In their efforts to understand human behavioral processes, the functional psychologists developed the technique of longitudinal research, which consists of interviewing, testing, and observing one person over a long period of time. Such a system permits the psychologist to observe and record the person”s development and how he or she reacts to different circumstances.
In the late 19th century Viennese neurologist Sigmund Freud developed a theory of personality and a system of psychotherapy known as psychoanalysis. According to this theory, people are strongly influenced by unconscious forces, including innate sexual and aggressive drives. In this 1938 British Broadcasting Corporation interview, Freud recounts the early resistance to his ideas and later acceptance of his work. Freud's speech is slurred because he was suffering from cancer of the jaw. He died the following year.
Alongside Wundt and James, a third prominent leader of the new psychology was Sigmund Freud, a Viennese neurologist of the late 19th and early 20th century. Through his clinical practice, Freud developed a very different approach to psychology. After graduating from medical school, Freud treated patients who appeared to suffer from certain ailments but had nothing physically wrong with them. These patients were not consciously faking their symptoms, and often the symptoms would disappear through hypnosis, or even just by talking. On the basis of these observations, Freud formulated a theory of personality and a form of psychotherapy known as psychoanalysis. It became one of the most influential schools of Western thought of the 20th century.
Freud introduced his new theory in The Interpretation of Dreams (1889), the first of 24 books he would write. The theory is summarized in Freud's last book, An Outline of Psychoanalysis, published in 1940, after his death. In contrast to Wundt and James, for whom psychology was the study of conscious experience, Freud believed that people are motivated largely by unconscious forces, including strong sexual and aggressive drives. He likened the human mind to an iceberg: The small tip that floats on the water is the conscious part, and the vast region beneath the surface comprises the unconscious. Freud believed that although unconscious motives can be temporarily suppressed, they must find a suitable outlet in order for a person to maintain a healthy personality.
To probe the unconscious mind, Freud developed the psychotherapy technique of free association. In free association, the patient reclines and talks about thoughts, wishes, memories, and whatever else comes to mind. The analyst tries to interpret these verbalizations to determine their psychological significance. In particular, Freud encouraged patients to free associate about their dreams, which he believed were the “royal road to the unconscious.” According to Freud, dreams are disguised expressions of deep, hidden impulses. Thus, as patients recount the conscious manifest content of dreams, the psychoanalyst tries to unmask the underlying latent content-what the dreams really mean.
From the start of psychoanalysis, Freud attracted followers, many of whom later proposed competing theories. As a group, these neo-Freudians shared the assumption that the unconscious plays an important role in a person”s thoughts and behaviors. Most parted company with Freud, however, over his emphasis on sex as a driving force. For example, Swiss psychiatrist Carl Jung theorized that all humans inherit a collective unconscious that contains universal symbols and memories from their ancestral past. Austrian physician Alfred Adler theorized that people are primarily motivated to overcome inherent feelings of inferiority. He wrote about the effects of birth order in the family and coined the term sibling rivalry. Karen Horney, a German-born American psychiatrist, argued that humans have a basic need for love and security, and become anxious when they feel isolated and alone.
Motivated by a desire to uncover unconscious aspects of the psyche, psychoanalytic researchers devised what are known as projective tests. A projective test asks people to respond to an ambiguous stimulus such as a word, an incomplete sentence, an inkblot, or an ambiguous picture. These tests are based on the assumption that if a stimulus is vague enough to accommodate different interpretations, then people will use it to project their unconscious needs, wishes, fears, and conflicts. The most popular of these tests are the Rorschach Inkblot Test, which consists of ten inkblots, and the Thematic Apperception Test, which consists of drawings of people in ambiguous situations.
Psychoanalysis has been criticized on various grounds and is not as popular as in the past. However, Freud's overall influence on the field has been deep and lasting, particularly his ideas about the unconscious. Today, most psychologists agree that people can be profoundly influenced by unconscious forces, and that people often have a limited awareness of why they think, feel, and behave as they do.
In 1885 German philosopher Hermann Ebbinghaus conducted one of the first studies on memory, using himself as a subject. He memorized lists of nonsense syllables and then tested his memory of the syllables at intervals ranging from 20 minutes to 31 days. As shown in this curve, he found that he remembered less than 40 percent of the items after nine hours, but that the rate of forgetting leveled off over time.
In addition to Wundt, James, and Freud, many other’s scholars helped to define the science of psychology. In 1885 German philosopher Hermann Ebbinghaus conducted a series of classic experiments on memory, using nonsense syllables to establish principles of retention and forgetting. In 1896 American psychologist Lightner Witmer opened the first psychological clinic, which initially treated children with learning disorders. He later founded the first journal and training program in a new helping profession that he named clinical psychology. In 1905 French psychologist Alfred Binet devised the first major intelligence test in order to assess the academic potential of schoolchildren in Paris. The test was later translated and revised by Stanford University psychologist Lewis Terman and is now known as the Stanford-Binet intelligence test. In 1908 American psychologist Margaret Floy Washburn (who later became the second female president of the American Psychological Association) wrote an influential book called The Animal Mind, in which she synthesized animal research to that time.
In 1912 German psychologist Max Wertheimer discovered that when two stationary lights flash in succession, people see the display as a single light moving back and forth. This illusion inspired the Gestalt psychology movement, which was based on the notion that people tend to perceive a well-organized whole or pattern that is different from the sum of isolated sensations. Other leaders of Gestalt psychology included Wertheimer”s close associates Wolfgang Köhler and Kurt Koffka. Later, German American psychologist Kurt Lewin extended Gestalt psychology to studies of motivation, personality, social psychology, and conflict resolution. German American psychologist Fritz Heider then extended this approach to the study of how people perceive themselves and others.
In the late 19th century, American psychologist Edward L. Thorndike conducted some of the first experiments on animal learning. Thorndike formulated the law of effect, which states that behaviors that are followed by pleasant consequences will be more likely to be repeated in the future.
William James had defined psychology as “the science of mental life.” But in the early 1900s, growing numbers of psychologists voiced criticism of the approach used by scholars to explore conscious and unconscious mental processes. These critics doubted the reliability and usefulness of the method of introspection, in which subjects are asked to describe their own mental processes during various tasks. They were also critical of Freud's emphasis on unconscious motives. In search of more-scientific methods, psychologists gradually turned away from research on invisible mental processes and began to study only behavior that could be observed directly. This approach, known as behaviorism, ultimately revolutionized psychology and remained the dominant school of thought for nearly 50 years.
Russian physiologist Ivan Pavlov discovered a major type of learning, classical conditioning, by accident while conducting experiments on digestion in the early 1900s. He devoted the rest of his life to discovering the underlying principles of classical conditioning.
Among the first to lay the foundation for the new behaviorism was American psychologist Edward Lee Thorndike. In 1898 Thorndike conducted a series of experiments on animal learning. In one study, he put cats into a cage, put food just outside the cage, and timed how long it took the cats to learn how to open an escape door that led to the food. Placing the animals in the same cage again and again, Thorndike found that the cats would repeat behaviors that worked and would escape more and more quickly with successive trials. Thorndike thereafter proposed the law of effect, which states that behaviors that are followed by a positive outcome are repeated, while those followed by a negative outcome or none at all are extinguished.
In 1906 Russian physiologist Ivan Pavlov-who had won a Nobel Prize two years earlier for his studies of digestion-stumbled onto one of the most important principles of learning and behavior. Pavlov was investigating the digestive process in dogs by putting food in their mouths and measuring the flow of saliva. He found that after repeated testing, the dogs would salivate in anticipation of the food, even before he put it in their mouth. He soon discovered that if he rang a bell just before the food was presented each time, the dogs would eventually salivate at the mere sound of the bell. Pavlov had discovered a basic form of learning called classical conditioning (also referred to as Pavlovian conditioning) in which an organism comes to associate one stimulus with another. Later research showed that this basic process can account for how people form certain preferences and fears.
American psychologist John B. Watson believed psychologists should study observable behavior instead of speculating about a person”s inner thoughts and feelings. Watson's approach, which he termed behaviorism, dominated psychology for the first half of the 20th century.
Although Thorndike and Pavlov set the stage for behaviorism, it was not until 1913 that a psychologist set forward a clear vision for behaviorist psychology. In that year John Watson, a well-known animal psychologist at Johns Hopkins University, published a landmark paper entitled “Psychology as the Behaviorist Views It.” Watson”s goal was nothing less than a complete redefinition of psychology. “Psychology as the behaviorist views it.” Watson wrote, “is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior.” Watson narrowly defined psychology as the scientific study of behavior. He urged his colleagues to abandon both introspection and speculative theories about the unconscious. Instead he stressed the importance of observing and quantifying behavior. In light of Darwin”s theory of evolution, he also advocated the use of animals in psychological research, convinced that the principles of behavior would generalize across all species.
American psychologist B. F. Skinner became famous for his pioneering research on learning and behavior. During his 60-year career, Skinner discovered important principles of operant conditioning, a type of learning that involves reinforcement and punishment. A strict behaviorist, Skinner believed that operant conditioning could explain even the most complex of human behaviors.
Many American psychologists were quick to adopt behaviorism, and animal laboratories were set up all over the country. Aiming to predict and control behavior, the "behaviorists” strategy was to vary a stimulus in the environment and observe an organism's response. They saw no need to speculate about mental processes inside the head. For example, Watson argued that thinking was simply talking to oneself silently. He believed that thinking could be studied by recording the movement of certain muscles in the throat.
American psychologist B. F. Skinner designed an apparatus, now called a Skinner box, that allowed him to formulate important principles of animal learning. An animal placed inside the box is rewarded with a small bit of food each time it makes the desired response, such as pressing a lever or pecking a key. A device outside the box records the animal”s responses.
The most forceful leader of behaviorism was B. F. Skinner, an American psychologist who began studying animal learning in the 1930s. Skinner coined the term reinforcement and invented a new research apparatus called the Skinner box for use in testing animals. Based on his experiments with rats and pigeons, Skinner identified a number of basic principles of learning. He claimed that these principles explained not only the behavior of laboratory animals, but also accounted for how human beings learn new behaviors or change existing behaviors. He concluded that nearly all behavior is shaped by complex patterns of reinforcement in a person”s environment, a process that he called operant conditioning (also referred to as instrumental conditioning). Skinner”s views on the causes of human behavior made him one of the most famous and controversial psychologists of the 20th century.
Operant conditioning, pioneered by American psychologist B. F. Skinner, is the process of shaping behavior by means of reinforcement and punishment. This illustration shows how a mouse can learn to maneuver through a maze. The mouse is rewarded with food when it reaches the first turn in the maze (A). Once the first behavior becomes ingrained, the mouse is not rewarded until it makes the second turn (B). After many times through the maze, the mouse must reach the end of the maze to receive its reward ©.
Skinner and others applied his findings to modify behavior in the workplace, the classroom, the clinic, and other settings. In World War II (1939-1945), for example, he worked for the U.S. government on a top-secret project in which he trained pigeons to guide an armed glider plane toward enemy ships. He also invented the first teaching machine, which allowed students to learn at their own pace by solving a series of problems and receiving immediate feedback. In his popular book Walden Two (1948), Skinner presented his vision of a behaviorist utopia, in which socially adaptive behaviors are maintained by rewards, or positive reinforcements. Throughout his career, Skinner held firm to his belief that psychologists should focus on the prediction and control of behavior.
Faced with a choice between psychoanalysis and behaviorism, many psychologists in the 1950s and 1960s sensed a void in psychology”s conception of human nature. Freud had drawn attention to the darker forces of the unconscious, and Skinner was interested only in the effects of reinforcement on observable behavior. Humanistic psychology was born out of a desire to understand the conscious mind, free will, human dignity, and the capacity for self-reflection and growth. An alternative to psychoanalysis and behaviorism, humanistic psychology became known as “the third force.”
The humanistic movement was led by American psychologists Carl Rogers and Abraham Maslow. According to Rogers, all humans are born with a drive to achieve their full capacity and to behave in ways that are consistent with their true selves. Rogers, a psychotherapist, developed person-centered therapy, a nonjudgmental, nondirective approach that helped clients clarify their sense of whom they are in an effort to facilitate their own healing process. At about the same time, Maslow theorized that all people are motivated to fulfill a hierarchy of needs. At the bottom of the hierarchy are basic physiological needs, such as hunger, thirst, and sleep. Further up the hierarchy are needs for safety and security, needs for belonging and love, and esteem-related needs for status and achievement. Once these needs are met, Maslow believed, people strive for self-actualization, the ultimate state of personal fulfillment. As Maslow put it: A musician must make music, an artist must paint, a poet must write, if he is ultimately to be at peace with himself. "What a man can be, he must be.
Swiss psychologist Jean Piaget based his early theories of intellectual development on his questioning and observation of his own children. From these and later studies, Piaget concluded that all children pass through a predictable series of cognitive stages.
From the 1920s through the 1960s, behaviorism dominated psychology in the United States. Eventually, however, psychologists began to move away from strict behaviorism. Many became increasingly interested in cognition, a term used to describe all the mental processes involved in acquiring, storing, and using knowledge. Such processes include perception, memory, thinking, problem solving, imagining, and language. This shift in emphasis toward cognition had such a profound influence on psychology that it has often been called the cognitive revolution. The psychological study of cognition became known as cognitive psychology.
One reason for psychologists” renewed interest in mental processes was the invention of the computer, which provided an intriguing metaphor for the human mind. The hardware of the computer was likened to the brain, and computer programs provided a step-by-step model of how information from the environment is input, stored, and retrieved to produce a response. Based on the computer metaphor, psychologists began to formulate information-processing models of human thought and behavior.
In the 1950s American linguist Noam Chomsky proposed that the human brain is especially constructed to detect and reproduce language and that the ability to form and understand language is innate to all human beings. According to Chomsky, young children learn and apply grammatical rules and vocabulary as they are exposed to them and do not require initial formal teaching.
The pioneering work of Swiss psychologist Jean Piaget also inspired psychologists to study cognition. During the 1920s, while administering intelligence tests in schools, Piaget became interested in how children think. He designed various tasks and interview questions to reveal how children of different ages reason about time, nature, numbers, causality, morality, and other concepts. Based on his many studies, Piaget theorized that from infancy to adolescence, children advance through a predictable series of cognitive stages.
The cognitive revolution also gained momentum from developments in the study of language. Behaviorist B. F. Skinner had claimed that language is acquired according to the laws of operant conditioning, in much the same way that rats learn to press a bar for food pellets. In 1959, however, American linguist Noam Chomsky charged that Skinner's account of language development was wrong. Chomsky noted that children all over the world start to speak at roughly the same age and proceed through roughly the same stages without being explicitly taught or rewarded for the effort. According to Chomsky, the human capacity for learning language is innate. He theorized that the human brain is “hardwired” for language as a product of evolution. By pointing to the primary importance of biological dispositions in the development of language, Chomsky”s theory dealt a serious blow to the behaviorist assumption that all human behaviors are formed and maintained by reinforcement.
Before psychology became established in science, it was popularly associated with extrasensory perception (ESP) and other paranormal phenomena (phenomena beyond the laws of science). Today, these topics lie outside the traditional scope of scientific psychology and fall within the domain of parapsychology. Psychologists note that thousands of studies have failed to demonstrate the existence of paranormal phenomena.
Grounded in the conviction that mind and behavior must be studied using statistical and scientific methods, psychology has become a highly respected and socially useful discipline. Psychologists now study important and sensitive topics such as the similarities and differences between men and women, racial and ethnic diversity, sexual orientation, marriage and divorce, abortion, adoption, intelligence testing, sleep and sleep disorders, obesity and dieting, and the effects of psychoactive drugs such as methylphenidate (Ritalin) and fluoxetine (Prozac).
In the last few decades, researchers have made significant breakthroughs in understanding the brain, mental processes, and behavior. This section of the article provides examples of contemporary research in psychology: the plasticity of the brain and nervous system, the nature of consciousness, memory distortions, competence and rationality, genetic influences on behavior, infancy, the nature of intelligence, human motivation, prejudice and discrimination, the benefits of psychotherapy, and the psychological influences on the immune system.
Psychologists once believed that the neural circuits of the adult brain and nervous system were fully developed and no longer subject to change. Then in the 1980s and 1990s a series of provocative experiments showed that the adult brain has flexibility, or plasticity-a capacity to change as a result of usage and experience.
These experiments showed that adult rats flooded with visual stimulation formed new neural connections in the brain's visual cortex, where visual signals are interpreted. Likewise, those trained to run an obstacle course formed new connections in the cerebellum, where balance and motor skills are coordinated. Similar results with birds, mice, and monkeys have confirmed the point: Experience can stimulate the growth of new connections and mold the brain”s neural architecture.
Once the brain reaches maturity, the number of neurons does not increase, and any neurons that are damaged are permanently disabled. But the plasticity of the brain can greatly benefit people with damage to the brain and nervous system. Organisms can compensate for loss by strengthening old neural connections and sprouting new ones. That is why people who suffer strokes are often able to recover their lost speech and motor abilities.
In 1860 German physicist Gustav Fechner theorized that if the human brain were divided into right and left halves, each side would have its own stream of consciousness. Modern medicine has actually allowed scientists to investigate this hypothesis. People who suffer from life-threatening epileptic seizures sometimes undergo a radical surgery that severs the corpus callosum, a bridge of nerve tissue that connects the right and left hemispheres of the brain. After the surgery, the two hemispheres can no longer communicate with each other.
Scientists have long considered the nature of consciousness without producing a fully satisfactory definition. In the early 20th century American philosopher and psychologist William James suggested that consciousness is a mental process involving both attention to external stimuli and short-term memory. Later scientific explorations of consciousness mostly expanded upon James”s work. In this article from a 1997 special issue of Scientific American, Nobel laureate Francis Crick, who helped determine the structure of DNA, and fellow biophysicist Christof Koch explain how experiments on vision might deepen our understanding of consciousness.
Beginning in the 1960s American neurologist Roger Sperry and others tested such split-brain patients in carefully designed experiments. The researchers found that the hemispheres of these patients seemed to function independently, almost as if the subjects had two brains. In addition, they discovered that the left hemisphere was capable of speech and language, but not the right hemisphere. For example, when split-brain patients saw the image of an object flashed in their left visual field (thus sending the visual information to the right hemisphere), they were incapable of naming or describing the object. Yet they could easily point to the correct object with their left hand (which is controlled by the right hemisphere). As Sperry”s colleague Michael Gazzaniga stated, “Each half brain seemed to work and function outside of the conscious realm of the other.”
Other psychologists interested in consciousness have examined how people are influenced without their awareness. For example, research has demonstrated that under certain conditions in the laboratory, people can be fleetingly affected by subliminal stimuli, sensory information presented so rapidly or faintly that it falls below the threshold of awareness. (Note, however, that scientists have discredited claims that people can be importantly influenced by subliminal messages in advertising, rock music, or other media.) Other evidence for influence without awareness comes from studies of people with a type of amnesia that prevents them from forming new memories. In experiments, these subjects are unable to recognize words they previously viewed in a list, but they are more likely to use those words later in an unrelated task. In fact, memory without awareness is normal, as when people come up with an idea they think is original, only later to realize that they had inadvertently borrowed it from another source.
Cognitive psychologists have often likened human memory to a computer that encodes, stores, and retrieves information. It is now clear, however, that remembering is an active process and that people construct and alter memories according to their beliefs, wishes, needs, and information received from outside sources.
Without realizing it, people sometimes create memories that are false. In one study, for example, subjects watched a slide show depicting a car accident. They saw either a “STOP” sign or a “YIELD” sign in the slides, but afterward they were asked a question about the accident that implied the presence of the other sign. Influenced by this suggestion, many subjects recalled the wrong traffic sign. In another study, people who heard a list of sleep-related words (bed, yawn) or music-related words (jazz, instrument) were often convinced moments later that they had also heard the words sleep or music-words that fit the category but were not on the list. In a third study, researchers asked college students to recall their high-school grades. Then the researchers checked those memories against the students” actual transcripts. The students recalled most grades correctly, but most of the errors inflated their grades, particularly when the actual grades were low. When scientists distinguish between human beings and other animals, they point to our larger cerebral cortex (the outer part of the brain) and to our superior intellect-as seen in the abilities to acquire and store large amounts of information, solve problems, and communicate through the use of language.
In recent years, however, those studying human cognition have found that people are often less than rational and accurate in their performance. Some researchers have found that people are prone to forgetting, and worse, that memories of past events are often highly distorted. Others have observed that people often violate the rules of logic and probability when reasoning about real events, as when gamblers overestimate the odds of winning in games of chance. One reason for these mistakes is that we commonly rely on cognitive heuristics, mental shortcuts that allow us to make judgments that are quick but often in error. To understand how heuristics can lead to mistaken assumptions, imagine offering people a lottery ticket containing six numbers out of a pool of the numbers 1 through 40. If given a choice between the tickets 6-39-2-10-24-30 or 1-2-3-4-5-6, most people select the first ticket, because it has the appearance of randomness. Yet out of the 3,838,380 possible winning combinations, both sequences are equally likely.
One of the oldest debates in psychology, and in philosophy, concerns whether individual human traits and abilities are predetermined from birth or due to one's upbringing and experiences. This debate is often termed the nature-nurture debate. A strict genetic (nature) position states that people are predisposed to become sociable, smart, cheerful, or depressed according to their genetic blueprint. In contrast, a strict environmental (nurture) position says that people are shaped by parents, peers, cultural institutions, and life experiences.
Research shows that the more genetically related a person is to someone with schizophrenia, the greater the risk that person has of developing the illness. For example, children of one parent with schizophrenia have a 13 percent chance of developing the illness, whereas children of two parents with schizophrenia have a 46 percent chance of developing the disorder.
Researchers can estimate the role of genetic factors in two ways: (1) twin studies and (2) adoption studies. Twin studies compare identical twins with fraternal twins of the same sex. If identical twins (who share all the same genes) are more similar to each other on a given trait than are same-sex fraternal twins (who share only about half of the same genes), then genetic factors are assumed to influence the trait. Other studies compare identical twins who are raised together with identical twins who are separated at birth and raised in different families. If the twins raised together are more similar to each other than the twins raised apart, childhood experiences are presumed to influence the trait. Sometimes researchers conduct adoption studies, in which they compare adopted children to their biological and adoptive parents. If these children display traits that resemble those of their biological relatives more than their adoptive relatives, genetic factors are assumed to play a role in the trait.
In recent years, several twin and adoption studies have shown that genetic factors play a role in the development of intellectual abilities, temperament and personality, vocational interests, and various psychological disorders. Interestingly, however, this same research indicates that at least 50 percent of the variation in these characteristics within the population is attributable to factors in the environment. Today, most researchers agree that psychological characteristics spring from a combination of the forces of nature and nurture.
Helpless to survive on their own, newborn babies nevertheless possess a remarkable range of skills that aid in their survival. Newborns can see, hear, taste, smell, and feel pain; vision is the least developed sense at birth but improves rapidly in the first months. Crying communicates their need for food, comfort, or stimulation. Newborns also have reflexes for sucking, swallowing, grasping, and turning their head in search of their mother”s nipple.
In 1890 William James described the newborn”s experience as “one great blooming, buzzing confusion.” However, with the aid of sophisticated research methods, psychologists have discovered that infants are smarter than was previously known.
A period of dramatic growth, infancy lasts from birth to around 18 months of age. Researchers have found that infants are born with certain abilities designed to aid their survival. For example, newborns show a distinct preference for human faces over other visual stimuli.
To learn about the perceptual world of infants, researchers measure infants” head movements, eye movements, facial expressions, brain waves, heart rate, and respiration. Using these indicators, psychologists have found that shortly after birth, infants show a distinct preference for the human face over other visual stimuli. Also suggesting that newborns are tuned into the face as a social object is the fact that within 72 hours of birth, they can mimic adults who purse the lips or stick out the tongue-a rudimentary form of imitation. Newborns can distinguish between their mother”s voice and that of another woman. And at two weeks old, nursing infants are more attracted to the body odor of their mother and other breast-feeding females than to that of other women. Taken together, these findings show that infants are equipped at birth with certain senses and reflexes designed to aid their survival.
In 1905 French psychologist Alfred Binet and colleague Théodore Simon devised one of the first tests of general intelligence. The test sought to identify French children likely to have difficulty in school so that they could receive special education. An American version of Binet”s test, the Stanford-Binet Intelligence Scale, is still used today.
In 1905 French psychologist Alfred Binet devised the first major intelligence test for the purpose of identifying slow learners in school. In doing so, Binet assumed that intelligence could be measured as a general intellectual capacity and summarized in a numerical score, or intelligence quotient (IQ). Consistently, testing has revealed that although each of us is more skilled in some areas than in others, a general intelligence underlies our more specific abilities.
Intelligence tests often play a decisive role in determining whether a person is admitted to college, graduate school, or professional school. Thousands of people take intelligence tests every year, but many psychologists and education experts question whether these tests are an accurate way of measuring who will succeed or fail in school and later in life. In this 1998 Scientific American article, psychology and education professor Robert J. Sternberg of Yale University in New Haven, Connecticut, presents evidence against conventional intelligence tests and proposes several ways to improve testing.
Today, many psychologists believe that there is more than one type of intelligence. American psychologist Howard Gardner proposed the existence of multiple intelligence, each linked to a separate system within the brain. He theorized that there are seven types of intelligence: linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, and intrapersonal. American psychologist Robert Sternberg suggested a different model of intelligence, consisting of three components: analytic (“school smarts,” as measured in academic tests), creative (a capacity for insight), and practical (“street smarts,” or the ability to size up and adapt to situations). Psychologists from all branches of the discipline study the topic of motivation, an inner state that moves an organism toward the fulfillment of some goal. Over the years, different theories of motivation have been proposed. Some theories state that people are motivated by the need to satisfy physiological needs, whereas others state that people seek to maintain an optimum level of bodily arousal (not too little and not too much). Still other theories focus on the ways in which people respond to external incentives such as money, grades in school, and recognition. Motivation researchers study a wide range of topics, including hunger and obesity, sexual desire, the effects of reward and punishment, and the needs for power, achievement, social acceptance, love, and self-esteem.
In 1954 American psychologist Abraham Maslow proposed that all people are motivated to fulfill a hierarchical pyramid of needs. At the bottom of Maslow”s pyramid are needs essential to survival, such as the needs for food, water, and sleep. The need for safety follows these physiological needs. According to Maslow, higher-level needs become important to us only after our more basic needs are satisfied. These higher needs include the need for love and belongingness, the need for esteem, and the need for self-actualization (in Maslow”s theory, a state in which people realize their greatest potential).
The view that the role of sentences in inference gives a more important key to their meaning than their “external” relations to things in the world. The meaning of a sentence becomes its place in a network of inferences that it legitimates. Also, known as its functional role semantics, procedural semantic or conceptual role semantics. As these view bear some relation to the coherence theory of truth, and suffers from the same suspicion that divorces meaning from any clear association with things in the world.
Paradoxes rest upon the assumption that analysis is a relation with concept, then are involving entities of other sorts, such as linguistic expressions, and that in true analysis, analysand and analysandum are one and the same concept. However, these assumptions are explicit in the British philosopher George Edward Moore, but some of Moore”s remarks hint at a solution that a statement of an analysis is a statement partially taken about the concept involved and partly about the verbal expression used to express it. Moore is to suggest that he thinks of a solution of this sort is bound to be right, however, facts to suggest one because he cannot reveal of any way in which the analysis can be as part of the expression.
Elsewhere, the possibility clearly does set of apparent incontrovertible premises giving unacceptable or contradictory conclusions. To solve a paradox will involve showing that either these hidden flaws in the premises, or what the reasoning is erroneous, or that the apparently unacceptable conclusion can, in fact, be tolerable. Paradoxes are therefore important in philosophy, for until one is solved it shows that there is something about our reasoning and our concepts that we do not understand. Famous families of paradoxes include the semantic paradoxes and Zeno's paradoxes. At the beginning of the 20th century, Russell's paradox and other set-theoretic paradoxes of set theory, while the Sorites paradox has led to the investigation of the semantics of vagueness, and fuzzy logic. Paradoxes are under their other titles. Much as there is as much as a puzzle arising when someone says “p but I do not believe that p.” What is said is not contradictory, since (for many instances of p) both parts of it could br. true. But the person nevertheless violates one presupposition of normal practice, namely that you assert something only if you believe it: By adding that you do not believe what you just said you undo the natural significance of the original act saying it.
Furthermore, the moral philosopher and epistemologist Bernard Bolzano (1781-1848), whose logical work was based on a strong sense of there being an ontological underpinning of science and epistemology, lying in a theory of the objective entailments masking up the structure of scientific theories. His ability to challenge wisdom and come up with startling new ideas, as a Christian philosopher whether than from any position of mathematical authority, that for considerations of infinity, Bolzano”s significant work was Paradoxin des Unenndlichen, written in retirement and translated into the English as Paradoxes of the Infinite. Here, Bolzano considered directly the points that had concerned Galileo-the conflicting result that seem to emerge when infinity is studied. Certainly most of the paradoxical statements encountered in the mathematical domain . . . are propositions which either immediately contain the idea of the infinite, or at least in some way or other depends upon that idea for their attempted proof.
Continuing, Bolzano looks at two possible approaches to infinity. One is simply the case of setting up a sequence of numbers, such as the whole numbers, and saying that as it cannot conceivably be said to have a last term, it is inherently infinite-not finite. It is easy enough to show that the whole numbers do not have a point at which they stop, giving a name to that last number whatever it might have been to call it “ultimate.” Then what”s wrong with ultimate + 1? Why is that not a whole number?
The second approach to infinity, which Bolzano ascribes in Paradoses of the Infinite to “some philosophers . . . Taking this approach describe his first conception of infinity as the “bad infinity.” Although the German philosopher Friedrich George Hegal (1770-1831) applies the conceptual form of infinity and points that it is, rather, the basis for a substandard infinity that merely reaches toward the absolute, but never reaches it. In Paradoses of the Infinite, he calls this form of potential infinity as a variable quantity knowing no limit to its growth (a definition adopted, even by many mathematicians) . . . always growing int the infinite and never reaching it. As far as Hegel and his colleagues were concerned, using this uprush, there was no need for a real infinity beyond some unreachable absolute. Instead we deal with a variable quality that is as big as we need it to be, or often in calculus as small as we need it to be, without ever reaching the absolute, ultimate, truly infinite.
Bolzano argues, though, that there is something else, an infinity that does not have this “whatever you need it to be” elasticity. In fact a truly infinite quantity (for example, the length of a straight line unbounded in either direction, meaning: The magnitude of the spatial entity containing all the points determined solely by their abstractly conceivable relation to two fixed points) does not by any means need to be variable, and in an adduced example it is in fact not variable. Conversely, it is quite possible for a quantity merely capable of being taken greater than we have already taken it, and of becoming larger than any pre-assigned (finite) quantity, nevertheless to mean at all times merely finitely, which holds in particular of every numerical quantity 1, 2, 3, 4, 5.
In other words, for Bolzano there could be a true infinity that was not a variable “something” that was only bigger than anything you might specify. Such a true infinity was the result of joining two pints together and extending that line in both directions without stopping. And what is more, he could separate off the demands of calculus, using a finite quality without ever bothering with the slippery potential infinity. Here was both a deeper understanding of the nature of infinity and the basis on which are built in his “safe” infinity free calculus.
This use of the inexhaustible follows on directly from most Bolzano”s criticism of the way that ∞we used as a variable something that would be bigger than anything you could specify, but never quite reached the true, absolute infinity. In Paradoxes of the Infinity Bolzano points out that is possible for a quantity merely capable of becoming larger than any other one pre-assigned (finite) quantity, nevertheless to remain at all times merely finite.
Bolzano intended tis as a criticism of the way infinity was treated, but Professor Jacquette sees it instead of a way of masking use of practical applications like calculus without the need for weasel words about infinity.
By replacing ∞with ¤ we do away with one of the most common requirements for infinity, but is there anything left that map out to the real world? Can we confine infinity to that pure mathematical other world, where anything, however unreal, can be constructed, and forget about it elsewhere? Surprisingly, this seems to have been the view, at least at one point in time, even of the German mathematician and founder of set-theory Georg Cantor (1845-1918), himself, whose comments in 1883, that only the finite numbers are real.
Keeping within the lines of reason, both the Cambridge mathematician and philosopher Frank Plumpton Ramsey (1903-30) and the Italian mathematician G. Peano (1858-1932) have been to distinguish logical paradoxes and that depend upon the notion of reference or truth (semantic notions), such are the postulates justifying mathematical induction. It ensures that a numerical series is closed, in the sense that nothing but zero and its successors can be numbers. In that any series satisfying a set of axioms can be conceived as the sequence of natural numbers. Candidates from set theory include the Zermelo numbers, where the empty set is zero, and the successor of each number is its unit set, and the von Neuman numbers, where each number is the set of all smaller numbers. A similar and equally fundamental complementarity exists in the relation between zero and infinity. Although the fullness of infinity is logically antithetical to the emptiness of zero, infinity can be obtained from zero with a simple mathematical operation. The division of many numbers by zero is infinity, while the multiplication of any number by zero is zero.
With the set theory developed by the German mathematician and logician Georg Cantor. From 1878 to 1807, Cantor created a theory of abstract sets of entities that eventually became a mathematical discipline. A set, as he defined it, is a collection of definite and distinguished objects in thought or perception conceived as a whole.
Cantor attempted to prove that the process of counting and the definition of integers could be placed on a solid mathematical foundation. His method was to repeatedly place the elements in one set into “one-to-one” correspondence with those in another. In the case of integers, Cantor showed that each integer (1, 2, 3, . . . n) could be paired with an even integer (2, 4, 6, . . . n), and, therefore, that the set of all integers was equal to the set of all even numbers.
Amazingly, Cantor discovered that some infinite sets were large than others and that infinite sets formed a hierarchy of greater infinities. After this failed attempt to save the classical view of logical foundations and internal consistency of mathematical systems, it soon became obvious that a major crack had appeared in the seemingly sold foundations of number and mathematics. Meanwhile, an impressive number of mathematicians began to see that everything from functional analysis to the theory of real numbers depended on the problematic character of number itself.
While, in the theory of probability Ramsey was the first to show how a personalised theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a “redundancy theory of truth,” which hr combined with radical views of the function of many kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentences affirmed in a scientific theory that use some term, e.g., “quark.” Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the “topic-neutral” structure of the theory, but removes any implications that we know what the term so treated denote. I t leaves open the possibility of identifying the theoretical item with whatever it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
It seems, that the most taken of paradoxes in the foundations of “set theory” as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no too easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed those paradoses like those of Russell nd the “barber” were due to such as the im predicative definitions, and therefore proposed banning them. But, it tuns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen as an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? Is there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all the special science? For much of the 20th century their questions were pursued in a high abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truths or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophically understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which stricture sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by “natural light” or reason, and (in religion versions of the theory) that express God”s will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God' s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supped of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount, from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of “moral” considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test they are the edicts of a divine lawmaker, or that they are truths of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situation ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kant's own applications of the notion are not always convincing, as for one cause of confusion in relating Kant's ethics to theories such additional expressivism is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something “unconditional” or “necessary” such as the voice of reason.
For whichever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in onself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such for being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of “deontological” approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive perceptive, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that thy can be external to the believer”s cognitively perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase “cognitively accessible” suggests the weak interpretation, the main intuitive motivation for internalism, viz. the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a coherent view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them).
The most prominent recent externalist views have been versions of reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true, but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in “normal” possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilist can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliablist condition is satisfied.
One sort of response to this latter sorts of objection is to “bite the bullet” and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adult's posse's knowledge, though not the weaker conviction (if such a conviction does exist) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, the an knowledge?`
A rather different use of the terms “internalism” and “externalism” has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual's mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as “direct reference” theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment -, e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc.-not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought “from the inside,” simply by reflection. If content is depending on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors-which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, by way that if part or all of the content of a belief inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of that content ss justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirement for justification. An internalist must insist that there are no justification relations of these sorts, that our internally associable content can either be justified or justly anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalist account of content is mistaken.
The process of moving from a provisional formulation of acceptance of some position to acceptance of others, is that the goal of logic and classical epistemology is to codify kinds of inference, and to provide principles for separating good from bad inherences.
The rule of reference begins by implicating of question through which it is asked “What the tortoise said to Achilles” in the journal “Mind” in 1895. Lewis Carroll raised the Zeno like problem of how a proof ever gets started.” Suppose I have as premise (1) p and (2) p ➞q. Can I infer q? Only, it seems, if I am sure of (3) (p & p p ➞q) ➞q. Can I then infer q? Only, it seems if I am sure that (4) (p & p ➞q & (p & p ➞q) ➞q) ➞q. For each new axiom (N) I need a further axiom (N. + 1) telling me that the set so far implies q, and the regress never stops, usual solution is to trat a system as containing not only axioms but also rules of reference allow only axioms, but also rules of inference, allowing movement from the axiom. The rule modus ponens slows us to pass from the first two premises to q. Carroll”s puzzle shows that it is essential to distinguish two theoretical categories, although there may be choice bout which theses to put in which category.
For the best of all possibilities that explains inference had first been formulated by Princeton philosopher Gilber Harnam. The idea in that when we have an easy to excavate, the idea is that when we have a best explanation of some phenomenon, we are entitled to repose confidence in it simply on that account. Sometimes thought to br. the lynchpin of scientific method, the principle is not easy to formulate and has come under attack, notably since our best current explanation of something may only be the best of a bad lot. There exist cases in which the best explanation is still not all that convincing, so other considerations than pure explanation success seem to play a role.
The philosopher Bas van Fraassen (The Scientific Image, 1980) explicated further in that constructive empiricism divides science into observation statement and theory statement. It holds that the latter are capable of strict truth and falsity, but maintains that the appropriate attitude is not to believe them, but only to accept them ss best as empirically adequate. It is often regarded as a variety of pragmatism or instrumentalism, although more orthodox varieties of those position deny that theoretic statements have truth-value. A related vie is held by the German philosopher Hans Valhinger (1854-1933), who, however, thinks that we ca be sure that theoretical statements are actually false. , In other words, theories are useful because they enable us to cope with what would otherwise be the unmanageable complexity of things. The doctrine bears some affinity to pragmatism, but differs in that Vaihlinger thinks that our useful theories are nevertheless really false.
Lectures published as Pragmatism, became the new name for old ways of thinking (1907) summed up James”s original contributions to the theory called pragmatism, a term first used by the American logician C. S. Peirce. James generalized the pragmatic method, developing it from a critique of the logical basis of the sciences into a basis for the evaluation of all experience. He maintained that the meaning of ideas is found only in terms of their possible consequences. If consequences are lacking, ideas are meaningless. James contended that this is the method used by scientists to define their terms and to test their hypotheses, which, if meaningful, entail predictions. The hypotheses can be considered true if the predicted events take place. On the other hand, most metaphysical theories are meaningless, because they entail no testable predictions. Meaningful theories, James argued, are instruments for dealing with problems that arise in experience.
According to James”s pragmatism, then, truth is that which works. One determines what works by testing propositions in experience. In so doing, one finds that certain propositions become true. As James put it, “Truth is something that happens to an idea” in the process of its verification; it is not a static property. This does not mean, however, that anything can be true. “The true is only the expedient in the way of our thinking, just as “the right” is only the expedient in the way of our behaving,” James maintained. One cannot believe whatever one want to believe, because such self-centered beliefs would not work out.
James was opposed to absolute metaphysical systems and argued against doctrines that describe reality as a unified, monolithic whole. In Essays in Radical Empiricism (1912), he argued for a pluralistic universe, denying that the world can be explained in terms of an absolute force or scheme that determines the interrelations of things and events. He held that the interrelations, whether they serve to hold things together or apart, are just as real as the things themselves.
By the end of his life, James had become world-famous as a philosopher and psychologist. In both fields, he functioned more as an originator of new thought than as a founder of dogmatic schools. His pragmatic philosophy was further developed by American philosopher John Dewey and others; later studies in physics by Albert Einstein made the theories of interrelations advanced by James appear prophetic.
Nevertheless, in science a way of looking at a field, this, however, as accorded through the lines of force whose evident physical reality o of the intervening medium whereby, the task of the philosopher of science has often been posed in terms of demarcating good or scientific theories from bad, unscientific ones wherefore he property of a statement or theory that it is capable of being refuted by experience. It a proper annunciation is accredited within the philosophy falsifiability, wherein scientific theory, as opposed to unfalsifaiability and noticeably psychoanalysis and historical materialism. The philosopher of science Raimund Karl Popper (1902-1994) whose idea was that it could be a positive virtue is a scientific theory that it is bold, conjectural, and goes beyond the evidence, but that it has to be capable of facing possible refutation. If every way that things turn out is compatible with it, then it is no longer a scientific theory, but for instance, an ideology or article of faith. Popper argued that the central virtue of science, as opposed to pseudo-science, is not that it puts forward the hypotheses that are confirmed by evidence. That is, they genuinely face the possibility of test and rejection through not confirming to evidences so gathered, that is to give no accent of te extent in which it is rational to rely upon scientific theory, however, the actual picture of acceptance and rejection of scientific hypotheses is more complex than Popper suggests. As perhaps, the view that everyday attributions of intention beliefs, and, meanings to other persons proceed via tacit use of a theory that enables one to construct of these interpretations as an explanation of their doing.
The view is commonly held along with “functionalism” according to which psychological states are theoretical entities, identified by te network of their causes ad effects. The theory-theory has different implications, depending upon which feature of theories is being stressed. Theories may be thought of as capable of as yielding predication and explanations, as achieved by a process of theorizing as answering to empirical evidence, that its principle describable without them, as liable to be overturned by newer and better theorise, and so on. The main problem with is with our understanding of others as the outcome of a piece of theorising is the non-existence of medium, in which his theory can be couched as the chid learns simultaneously with the minds language.
Our understanding of others is not gained by the tacit use of a “theory,” enabling us to infer what thoughts or intentions explain their action, but by reliving the situation “in their moccasins” or from their point of view, not thereby understanding what they experienced and thought, and therefore expressed. Understanding others is achieved when we can ourselves deliberate as they did, and hear their words if theory are our own. The suggestion is a modern development of the “verstehe,” the tradition associated with the German philosopher, literary critic and historian Wilhelm Dilthey (1833-1911).
In addition, the hypnotise especially associated with the American philosopher of mind J.A. Fodor, who affirmed strongly that mental processing occurs in a language different from one”s ordinary native language, but underlying and explaining our competence with it. The idea is a development of the “Chomskyan” notion if an innate universal grammar, it is a way of drawing three analogies between the workings of the brain or mind and those of a standard computer, since computer programs are linguistically complex sets of instruction whose execution explains the surface behaviour of the computer. As an explanation of ordinary language learning and competence the hypothecs of thought have not found universal favour. It apparently only explains ordinary representational powers by invoking innate things of the same sort, and it invites the image of the learning infant translating the language surrounding and in back into an innate language whose own powers are a mysterious biological given.
In philosophy, the doctrine that all existence is resolvable into matter or into an attribute or effect of matter. According to this doctrine, matter is the ultimate reality, and the phenomenon of consciousness is explained by physicochemical changes in the nervous system. Materialism is thus the antithesis of idealism, in which the supremacy of mind is affirmed and matter is characterized as an aspect or objectification of mind. Extreme or absolute materialism is known as materialistic monism. According to the mind-stuff theory of monism, as expounded by the British metaphysician W. K. Clifford, in his Elements of Dynamic (1879-87), matters and minds are consubstantial, each being merely an aspect of the other. Philosophical materialism is ancient and has had numerous formulations. The early Greek philosophers subscribed to a variant of materialism known as hylozoism, according to which matter and life are identical. Related to hylozoism is the doctrine of hylotheism, in which matter is held to be divine, or the existence of God is disavowed apart from matter. Cosmological materialism is a term used to characterize a materialistic interpretation of the universe.
Antireligious materialism is motivated by a spirit of hostility toward the theological dogmas of organized religion, particularly those of Christianity. Notable among the exponents of antireligious materialism was the 18th-century French philosopher's Denis Diderot, Paul Henri d'Holbach, and Julien Offroy de La Mettrie. According to historical materialism, as set forth in the writings of Karl Marx, Friedrich Engels, and Vladimir Ilich Lenin, in every historical epoch the prevailing economic system by which the necessities of life are produced determines the form of societal organization and the political, religious, ethical, intellectual, and artistic history of the epoch.
In modern times philosophical materialism has been largely influenced by the doctrine of evolution and may indeed be said to have been assimilated in the wider theory of evolution. Supporters of the theory of evolution go beyond the mere antithesis or atheism of materialism and seek positively to show how the diversities and differences in creation are the result of natural as opposed to supernatural processes.
The Philosophy of Mind is the branch of philosophy that considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
Many fields other than philosophy shares an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousnesses, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
Descartes believed there are two basic kinds of things in the world, a belief known as substance dualism. For Descartes, the principles of existence for these two groups of things-bodies and minds-are completely different from one another: Bodies exist by being extended in space, while minds exist by being conscious. According to Descartes, nothing can be done to give a body thought and consciousness. No matter how we shape a body or combine it with other bodies, we cannot turn the body into a mind, a thing that is conscious, because being conscious is not a way of being extended.
For Descartes, a person consists of a human body and a human mind causally interacting with one another. For example, the intentions of a human being may cause that person's limbs to move. In this way, the mind can affect the body. In addition, the sense organs of a human being maybe affected by light, pressure, or sound, external sources, which in turn affect the brain, affecting mental states. Thus, the body may affect the mind. Exactly how mind can affect body, and vice versa, is a central issue in the philosophy of mind, and is known as the mind-body problem. According to Descartes, this interaction of mind and body is peculiarly intimate. Unlike the interaction between a pilot and his ship, the connection between mind and body more closely resembles two substances that have been thoroughly mixed together.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property dualists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as Eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person's identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes's view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. These link of memory, rather than a single underlying substance, provide the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
The field of artificial intelligence also raises interesting questions for the philosophy of mind. People have designed machines that mimic or model many aspects of human intelligence, and there are robots currently in use whose behavior is described in terms of goals, beliefs, and perceptions. Such machines are capable of behavior that, were it exhibited by a human being, would surely be taken to be free and creative. As an example, in 1996 an IBM computer named Deep Blue won a chess game against Russian world champion Garry Kasparov under international match regulations. Moreover, it is possible to design robots that have some sort of privileged access to their internal states. Philosophers disagree over whether such robots truly think or simply appear to think and whether such robots should be considered to be conscious.
Philosophy, a speculative world-view which asserts that basic reality is constantly in a process of flux and change. Indeed, reality is identified with pure process. Concepts such as creativity, freedom, novelty, emergence, and growth are fundamental explanatory categories for process philosophy. This metaphysical perspective is to be contrasted with a philosophy of substance, the view that a fixed and permanent reality underlies the changing or fluctuating world of ordinary experience. Whereas substance philosophy emphasizes static being, process philosophy emphasizes dynamically becoming.
Although process philosophy is as old as the 6th-century Bc Greek philosopher, Heraclitus, renewed interest in it was stimulated in the 19th century by the theory of evolution. Key figures in the development of modern process philosophy were the British philosophers's Herbert Spencer, Samuel Alexander, and Alfred North Whitehead, the American philosopher”s Charles S. Peirce and William James, and the French philosopher's Henri Bergson and Pierre Teilhard de Chardin. Whitehead's Process and Reality: An Essay in Cosmology (1929) is generally considered the most important systematic expression of process philosophy.
A contemporary theology has been strongly influenced by process philosophy. The American theologian Charles Hartshorne, for instance, rather than interpreting God as an unchanging absolute, emphasizes God”s sensitive and caring relationship with the world. A personal God enters into relationships in such a way that he is affected by the relationships, and to be affected by relationships is to change. So God too is in the process of growth and development.
Neurophysiology, is the study of how nerve cells, or neurons, receive and transmit information. Two types of phenomena are involved in processing nerve signals: electrical and chemical. Electrical events propagate a signal within a neuron, and chemical processes transmit the signal from one neuron to another neuron or to a muscle cell.
The signals conveying everything that human beings sense and think, and every motion they make, follows nerve pathways in the human body as waves of ions (atoms or groups of atoms that carries electric charges). Australian physiologist Sir John Eccles discovered many of the intricacies of this electrochemical signaling process, particularly the pivotal step in which a signal is conveyed from one nerve cell to another. He shared the 1963 Nobel Prize in physiology or medicine for this work, which he described in a 1965 Scientific American article.
A neuron is a long cell that has a thick central area containing the nucleus; it also has one long process called an axon and one or more short, bushy processes called dendrites. Dendrites receive impulses from other neurons. (The exceptions are sensory neurons, such as those that transmit information about temperature or touch, in which the signal is generated by specialized receptors in the skin.) These impulses are propagated electrically along the cell membrane to the end of the axon. At the tip of the axon the signal is chemically transmitted to an adjacent neuron or muscle cell.
Like all other cells, neurons contain charged ions: potassium and sodium (positively charged) and chlorine (negatively charged). Neurons differ from other cells in that they are able to produce a nerve impulse. A neuron is polarized-that is, it has an overall negative charge inside the cell membrane because of the high concentration of chlorine ions and low concentration of potassium and sodium ions. The concentration of these same ions is exactly reversed outside the cell. This charge differential represents stored electrical energy, sometimes referred to as membrane potential or resting potential. The negative charge inside the cell is maintained by two features. The first is the selective permeability of the cell membrane, which is more permeable to potassium than sodium. The second feature is sodium pumps within the cell membrane that actively pump sodium out of the cell. When depolarization occurs, this charge differential across the membrane is reversed, and a nerve impulse is produced.
Depolarization is a rapid change in the permeability of the cell membrane. When sensory input or any other kind of stimulating current is received by the neuron, the membrane permeability is changed, allowing a sudden influx of sodium ions into the cell. The high concentration of sodium, or action potential, changes the overalls charge within the cell from negative too positively. The locals change in ion concentration triggers similar reactions along the membrane, propagating the nerve impulse. After a brief period called the refractory period, during which the ionic concentration returned to resting potential, the neuron can repeat this process.
Nerve impulses travel at different speeds, depending on the cellular composition of a neuron. Where speed of impulse is important, as in the nervous system, axons are insulated with a membranous substance called myelin. The insulation provided by myelin maintains the ionic charge over long distances. Nerve impulses are propagated at specific points along the myelin sheath; these points are called the nodes of Ranvier. Examples of myelinated axons are those in sensory nerve fibers and nerves connected to skeletal muscles. In non-myelinated cells, the nerve impulse is propagated more diffusely.
When the electrical signal reaches the tip of an axon, it stimulates small presynaptic vesicles in the cell. These vesicles contain chemicals called neurotransmitters, which are released into the microscopic space between neurons (the synaptic cleft). The neurotransmitters attach to specialized receptors on the surface of the adjacent neuron. This stimulus causes the adjacent cell to depolarize and propagate an action potential of its own. The duration of a stimulus from a neurotransmitter is limited by the breakdown of the chemicals in the synaptic cleft and the reuptake by the neuron that produced them. Formerly, each neuron was thought to make only one transmitter, but recent studies have shown that some cells make two or more.
Philosophy of Mind considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
In the 17th century, French philosopher René Descartes proposed that only two substances ultimately exist; mind and body. Yet, if the two are entirely distinct, as Descartes believed, how can one substance interact with the other? How, for example, is the intention of a human mind able to cause movement in the person's limbs? The issue of the interaction between mind and body is known in philosophy as the mind-body problem.
Many fields other than a philosophy share an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former for being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Scientists have long considered the nature of consciousness without producing a fully satisfactory definition. In the early 20th century American philosopher and psychologist William James suggested that consciousness is a mental process involving both attention to external stimuli and short-term memory. Later scientific explorations of consciousness mostly expanded upon James”s work. In this article from a 1997 special issue of Scientific American, Nobel laureate Francis Crick, who helped determine the structure of DNA, and fellow biophysicists Christof Koch explains how experiments on vision might deepen our understanding of consciousness.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousnesses, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property dualists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as Eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own mental phenomena by introspection and because we use the general principles we understand about mental phenomena to predict and explain the behavior of others.
Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person's identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes's view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. These link of memory, rather than a single underlying substance, provide the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
No simple, agreed-upon definition of consciousness exists. Attempted definitions tend to be tautological (for example, consciousness defined as awareness) or merely descriptive (for example, consciousness described as sensations, thoughts, or feelings). Despite this problem of definition, the subject of consciousness has had a remarkable history. At one time the primary subject matter of psychology, consciousness as an area of study suffered an almost total demise, later reemerging to become a topic of current interest.
Most of the philosophical discussions of consciousness arose from the mind-body issues posed by the French philosopher and mathematician René Descartes in the 17th century. Descartes asked: Is the mind, or consciousness, independent of matter? Is consciousness extended (physical) or unextended (nonphysical)? Is consciousness determinative, or is it determined? English philosophers such as John Locke equated consciousness with physical sensations and the information they provide, whereas European philosophers such as Gottfried Wilhelm Leibniz and Immanuel Kant gave a more central and active role to consciousness.
The philosopher who most directly influenced subsequent exploration of the subject of consciousness was the 19th-century German educator Johann Friedrich Herbart, who wrote that ideas had quality and intensity and that they may inhibit or facilitate one another. Thus, ideas may pass from “states of reality” (consciousness) to “states of tendencies” (unconsciousness), with the dividing line between the two states being described as the threshold of consciousness. This formulation of Herbart clearly presages the development, by the German psychologist and physiologist Gustav Theodor Fechner, of the psychophysical measurement of sensation thresholds, and the later development by Sigmund Freud of the concept of the unconscious.
The experimental analysis of consciousness dates from 1879, when the German psychologist Wilhelm Max Wundt started his research laboratory. For Wundt, the task of psychology was the study of the structure of consciousness, which extended well beyond sensations and included feelings, images, memory, attention, duration, and movement. Because early interest focused on the content and dynamics of consciousness, it is not surprising that the central methodology of such studies was introspection; that is, subjects reported on the mental contents of their own consciousness. This introspective approach was developed most fully by the American psychologist Edward Bradford Titchener at Cornell University. Setting his task as that of describing the structure of the mind, Titchener attempted to detail, from introspective self-reports, the dimensions of the elements of consciousness. For example, taste was “dimensionalized” into four basic categories: sweet, sour, salt, and bitter. This approach was known as structuralism.
By the 1920s, however, a remarkable revolution had occurred in psychology that was to essentially remove considerations of consciousness from psychological research for some 50 years: Behaviorism captured the field of psychology. The main initiator of this movement was the American psychologist John Broadus Watson. In a 1913 article, Watson stated, “I believe that we can write a psychology and never use the term”s consciousness, mental states, mind . . . imagery and the like.” Psychologists then turned almost exclusively to behavior, as described in terms of stimulus and response, and consciousness was totally bypassed as a subject. A survey of eight leading introductory psychology texts published between 1930 and the 1950s found no mention of the topic of consciousness in five texts, and in two it was treated as a historical curiosity.
Beginning in the late 1950s, however, interest in the subject of consciousness returned, specifically in those subjects and techniques relating to altered states of consciousness: sleep and dreams, meditation, biofeedback, hypnosis, and drug-induced states. Much of the surge in sleep and dream research was directly fueled by a discovery relevant to the nature of consciousness. A physiological indicator of the dream state was found: At roughly 90-minute intervals, the eyes of sleepers were observed to move rapidly, and at the same time the sleepers” brain waves would show a pattern resembling the waking state. When people were awakened during these periods of rapid eye movement, they almost always reported dreams, whereas if awakened at other times they did not. This and other research clearly indicated that sleep, once considered a passive state, were instead an active state of consciousness.
During the 1960s, an increased search for “higher levels” of consciousness through meditation resulted in a growing interest in the practices of Zen Buddhism and Yoga from Eastern cultures. A full flowering of this movement in the United States was seen in the development of training programs, such as Transcendental Meditation, that were self-directed procedures of physical relaxation and focused attention. Biofeedback techniques also were developed to bring body systems involving factors such as blood pressure or temperature under voluntary control by providing feedback from the body, so that subjects could learn to control their responses. For example, researchers found that persons could control their brain-wave patterns to some extent, particularly the so-called alpha rhythms generally associated with a relaxed, meditative state. This finding was especially relevant to those interested in consciousness and meditation, and a number of “alpha training” programs emerged.
Another subject that led to increased interest in altered states of consciousness was hypnosis, which involves a transfer of conscious control from the subject to another person. Hypnotism has had a long and intricate history in medicine and folklore and has been intensively studied by psychologists. Much has become known about the hypnotic state, relative to individual suggestibility and personality traits; the subject has now largely been demythologized, and the limitations of the hypnotic state are fairly well known. Despite the increasing use of hypnosis, however, much remains to be learned about this unusual state of focused attention.
Finally, many people in the 1960s experimented with the psychoactive drugs known as hallucinogens, which produce disorders of consciousness. The most prominent of these drugs are lysergic acid diethylamide, or LSD; mescaline; and psilocybin; the latter two have long been associated with religious ceremonies in various cultures. LSD, because of its radical thought-modifying properties, was initially explored for its so-called mind-expanding potential and for its psychotomimetic effects (imitating psychoses). Little positive use, however, has been found for these drugs, and their use is highly restricted.
As the concept of a direct, simple linkage between environment and behavior became unsatisfactory in recent decades, the interest in altered states of consciousness may be taken as a visible sign of renewed interest in the topic of consciousness. That persons are active and intervening participants in their behavior has become increasingly clear. Environments, rewards, and punishments are not simply defined by their physical character. Memories are organized, not simply stored. An entirely new area called cognitive psychology has emerged that centers on these concerns. In the study of children, increased attention is being paid to how they understand, or perceive, the world at different ages. In the field of animal behavior, researchers increasingly emphasize the inherent characteristics resulting from the way a species has been shaped to respond adaptively to the environment. Humanistic psychologists, with a concern for self-actualization and growth, have emerged after a long period of silence. Throughout the development of clinical and industrial psychology, the conscious states of persons in terms of their current feelings and thoughts were of obvious importance. The role of consciousness, however, was often deemphasized in favor of unconscious needs and motivations. Trends can be seen, however, toward a new emphasis on the nature of states of consciousness.
Neurophysiology, is the study of how nerve cells, or neurons, receive and transmit information. Two types of phenomena are involved in processing nerve signals: electrical and chemical. Electrical events propagate a signal within a neuron, and chemical processes transmit the signal from one neuron to another neuron or to a muscle cell.
The signals conveying everything that human beings sense and think, and every motions they make, follow nerve pathways in the human body as waves of ions (atoms or groups of atoms that carries electric charges). Australian physiologist Sir John Eccles discovered many of the intricacies of this electrochemical signaling process, particularly the pivotal step in which a signal is conveyed from one nerve cell to another. He shared the 1963 Nobel Prize in physiology or medicine for this work, which he described in a 1965 Scientific American article.
A neuron is a long cell that has a thick central area containing the nucleus; it also has one long process called an axon and one or more short, bushy processes called dendrites. Dendrites receive impulses from other neurons. (The exceptions are sensory neurons, such as those that transmit information about temperature or touch, in which the signal is generated by specialized receptors in the skin.) These impulses are propagated electrically along the cell membrane to the end of the axon. At the tip of the axon the signal is chemically transmitted to an adjacent neuron or muscle cell.
Like all other cells, neurons contain charged ions: potassium and sodium (positively charged) and chlorine (negatively charged). Neurons differ from other cells in that they are able to produce a nerve impulse. A neuron is polarized-that is, it has an overall negative charge inside the cell membrane because of the high concentration of chlorine ions and low concentration of potassium and sodium ions. The concentration of these same ions is exactly reversed outside the cell. This charge differential represents stored electrical energy, sometimes referred to as membrane potential or resting potential. The negative charge inside the cell is maintained by two features. The first is the selective permeability of the cell membrane, which is more permeable to potassium than sodium. The second feature is sodium pumps within the cell membrane that actively pump sodium out of the cell. When depolarization occurs, this charge differential across the membrane is reversed, and a nerve impulse is produced.
Depolarization is a rapid change in the permeability of the cell membrane. When sensory input or any other kind of stimulating current is received by the neuron, the membrane permeability is changed, allowing a sudden influx of sodium ions into the cell. The high concentration of sodium, or action potential, changes the overall charges within the cell from negative too positively. The local changes in ion concentration triggers similar reactions along the membrane, propagating the nerve impulse. After a brief period called the refractory period, during which the ionic concentration returned to resting potential, the neuron can repeat this process.
Nerve impulses travel at different speeds, depending on the cellular composition of a neuron. Where speed of impulse is important, as in the nervous system, axons are insulated with a membranous substance called myelin. The insulation provided by myelin maintains the ionic charge over long distances. Nerve impulses are propagated at specific points along the myelin sheath; these points are called the nodes of Ranvier. Examples of myelinated axons are those in sensory nerve fibers and nerves connected to skeletal muscles. In non-myelinated cells, the nerve impulse is propagated more diffusely.
When the electrical signal reaches the tip of an axon, it stimulates small presynaptic vesicles in the cell. These vesicles contain chemicals called neurotransmitters, which are released into the microscopic space between neurons (the synaptic cleft). The neurotransmitters attach to specialized receptors on the surface of the adjacent neuron. This stimulus causes the adjacent cell to depolarize and propagate an action potential of its own. The duration of a stimulus from a neurotransmitter is limited by the breakdown of the chemicals in the synaptic cleft and the reuptake by the neuron that produced them. Formerly, each neuron was thought to make only one transmitter, but recent studies have shown that some cells make two or more.
All human emotions-including love, hate, fear, anger, elation, and sadness-are controlled by the brain. It also receives and interprets the countless signals that are sent to it from other parts of the body and from the external environment. The brain makes us conscious, emotional, and intelligent.
The adult human brain is a 1.3-kg. (3-lb.) mass of pinkish-gray jellylike tissue made up of approximately 100 billion nerve cells, or neurons; neuroglia (supporting-tissue) cells; and vascular (blood-carrying) and other tissues.
Between the brain and the cranium-the part of the skull that directly covers the brain-are three protective membranes, or meninges. The outermost membrane, the dura mater, is the toughest and thickest. Below the dura mater is a middle membrane, called the arachnoid layer. The innermost membrane, the pia mater, consists mainly of small blood vessels and follows the contours of the surface of the brain.
A clear liquid, the cerebrospinal fluid, bathes the entire brain and fills a series of four cavities, called ventricles, near the center of the brain. The cerebrospinal fluid protects the internal portion of the brain from varying pressures and transports chemical substances within the nervous system.
From the outside, the brain appears as three distinct but connected parts: the cerebrum (the Latin word for brain)-two large, almost symmetrical hemispheres; the cerebellum (“little brain”)-whose smaller hemispheres located at the back of the cerebrum; and the brain stem-a central core that gradually becomes the spinal cord, exiting the skull through an opening at its base called the foramen magnum. Two other major parts of the brain, the thalamus and the hypothalamus, lie in the midline above the brain stem underneath the cerebellum.
The brain and the spinal cord together make up the central nervous system, which communicates with the rest of the body through the peripheral nervous system. The peripheral nervous system consists of 12 pairs of cranial nerves extending from the cerebrum and brain stem; a system of other nerves branching throughout the body from the spinal cord; and the autonomic nervous system, which regulates vital functions not too conscious control, such as the activity of the heart muscle, smooth muscle (involuntary muscle found in the skin, blood vessels, and internal organs), and glands.
Most high-level brain functions take place in the cerebrum. Its two large hemispheres make up approximately 85 percent of the brain”s weight. The exterior surface of the cerebrum, the cerebral cortex, is a convoluted, or folded, grayish layer of cell bodies known as the gray matter. The gray matter covers an underlying mass of fibers called the white matter. The convolutions are made up of ridgelike bulges, known as gyri, separated by small grooves called sulci and larger grooves called fissures. Approximately two-thirds of the cortical surface is hidden in the folds of the sulci. The extensive convolutions enable a very large surface area of brain cortex-about 1.5 m2 (16 ft2) in an adult-to fit within the cranium. The pattern of these convolutions is similar, although not identical, in all humans.
The two cerebral hemispheres are partially separated from each other by a deep fold known as the longitudinal fissure. Communication between the two hemispheres is through several concentrated bundles of axons, called commissaries, the largest of which is the corpus callosum.
Several major sulci-divide the cortex into distinguishable regions. The central sulcus, or Rolandic fissures, runs from the middle of the top of each hemisphere downward, forward, and toward another major sulcus, the lateral (“side”), or Sylvian, sulcus. These and other sulci and gyri divide the cerebrum into five lobes: the frontal, parietal, temporal, and occipital lobes and the insula.
The frontal lobe is the largest of the five and consists of all the cortex in front of the central sulcus. Broca”s area, a part of the cortex related to speech, is located in the frontal lobe. The parietal lobe consists of the cortex behind the central sulcus to a sulcus near the back of the cerebrum known as the parietocipital sulcus. The parieto-occipital sulcus, in turn, forms the front border of the occipital lobe, which is the rearmost part of the cerebrum. The temporal lobe is to the side of and below the lateral sulcus. Wernicke”s area, a part of the cortex related to the understanding of language, is located in the temporal lobe. The insula lies deep within the folds of the lateral sulcus.
The cerebrum receives information from all the sense organs and sends motor commands (signals that results in activity in the muscles or glands) to other parts of the brain and the rest of the body. Motor commands are transmitted by the motor cortex, a strip of cerebral cortex extending from side to side across the top of the cerebrum just in front of the central sulcus. The sensory cortex, a parallel strips of cerebral cortex just in back of the central sulcus, receives input from the sense organs.
Many other areas of the cerebral cortex have also been mapped according to their specific functions, such as vision, hearing, speech, emotions, language, and other aspects of perceiving, thinking, and remembering. Cortical regions known as associative cortices are responsible for integrating multiple inputs, processing the information, and carrying out complex responses.
The cerebellum coordinates body movements. Located at the lower back of the brain beneath the occipital lobes, the cerebellum is divided into two lateral (side-by-side) lobes connected by a fingerlike bundle of white fibers called the vermis. The outer layer, or cortex, of the cerebellum consists of fine folds called folia. As in the cerebrum, the outer layer of cortical gray matter surrounds a deeper layer of white matter and nuclei (groups of nerve cells). Three fiber bundles called cerebellar peduncles connect the cerebellum to the three parts of the brain stem-the midbrain, the pons, and the medulla oblongata.
The cerebellum coordinates voluntary movements by fine-tuning commands from the motor cortex in the cerebrum. The cerebellum also maintains posture and balance by controlling muscle tone and sensing the position of the limbs. All motor activity, from hitting a baseball to fingering a violin, depends on the cerebellum.
The thalamus and the hypothalamus lie underneath the cerebrum and connect it to the brain stem. The thalamus consist of two rounded masses of gray tissue lying within the middle of the brain, between the two cerebral hemispheres. The thalamus are the main relay station for incoming sensory signals to the cerebral cortex and for outgoing motor signals from it. All sensory input to the brain, except that of the sense of smell, connects to individual nuclei of the thalamus.
The hypothalamus lies beneath the thalamus on the midline at the base of the brain. It regulates or is involved directly in the control of many of the body's vital drives and activities, such as eating, drinking, temperature regulation, sleep, emotional behavior, and sexual activity. It also controls the function of internal body organs by means of the autonomic nervous system, interacts closely with the pituitary gland, and helps coordinate activities of the brain stem.
The brain stem is revolutionarily the most primitive part of the brain and is responsible for sustaining the basic functions of life, such as breathing and blood pressure. It includes three main structures lying between and below the two cerebral hemispheres-the midbrain, pons, and medulla oblongata.
The topmost structure of the brain stem is the midbrain. It contains major relay stations for neurons transmitting signals to the cerebral cortex, as well as many reflex centers-pathways carrying sensory (input) information and motor (output) command. Relay and reflex centers for visual and auditory (hearing) functions are located in the top portion of the midbrain. A pair of nuclei called the superior colliculus control reflex actions of the eye, such as blinking, opening and closing the pupil, and focusing the lens. A second pair of nuclei, called the inferior colliculus, controls auditory reflexes, such as adjusting the ear to the volume of sound. At the bottom of the midbrain are reflex and relay centers relating to pain, temperature, and touch, as well as several regions associated with the control of movement, such as the red nucleus and the substantia nigra and directly in front of the cerebellum is a prominent bulge in the brain stem called the pons. The pons consists of large bundles of nerve fibers that connect the two halves of the cerebellum and also connect each side of the cerebellum with the opposite-side cerebral hemisphere. The pons serves mainly as a relay station linking the cerebral cortex and the medulla oblongata.
The long, stalk-like lowermost portion of the brain stem is called the medulla oblongata. At the top, it is continuous with the pons and the midbrain; at the bottom, it makes a gradual transition into the spinal cord at the foramen magnum. Sensory and motor nerve fibers connecting the brain and the rest of the body cross over to the opposite side as they pass through the medulla. Thus, the left half of the brain communicates with the right half of the body, and the right half of the brain with the left half of the body.
Running up the brain stem from the medulla oblongata through the pons and the midbrain is a netlike formation of nuclei known as the reticular formation. The reticular formation controls respiration, cardiovascular function digestion, levels of alertness, and patterns of sleep. It also determines which parts of the constant flow of sensory information into the body are received by the cerebrum.
There are two main types of brain cells: neurons and neuroglia. Neurons are responsible for the transmission and analysis of all electrochemical communication within the brain and other parts of the nervous system. Each neuron is composed of a cell body called a soma. A major fiber called an axon, and a system of branches called dendrites. Axons, also called nerve fibers, convey electrical signals away from the soma and can be up to 1 m. (3.3 ft.) in length. Most axons are covered with a protective sheath of myelin, a substance made of fats and protein, which insulates the axon. Myelinated axons conduct neuronal signals faster than do unmyelinated axons. Dendrites convey electrical signals toward the soma, are shorter than axons, and are usually multiple and branching.
Neuroglial cells are twice as numerous as neurons and account for half of the brain”s weight. Neuroglia (from glia, Greek for “glue”) provides structural support to the neurons. Neuroglial cells also form myelin, guide developing neurons, take up chemicals involved in cell-to-cell communication, and contribute to the maintenance of the environment around neurons.
Twelve pairs of cranial nerves arise symmetrically from the base of the brain and are numbered, from front to back, in the order in which they arise. They connect mainly with structures of the head and neck, such as the eyes, ears, nose, mouth, tongue, and throat. Some are motor nerves, controlling muscle movement; some are sensory nerves, conveying information from the sense organs; and others contain fibers for both sensory and motor impulses. The first and second pairs of cranial nerves-the olfactory (smell) nerve and the optic (vision) nerve-carry, sensory information from the nose and eyes, respectively, to the undersurface of the cerebral hemispheres. The other ten pairs of cranial nerves originate in or end in the brain stem.
The brain functions by complex neuronal, or nerve cell, circuits. Communication between neurons is both electrical and chemical and always travels from the dendrites of a neuron, through its soma, and out its axon to the dendrites of another neuron.
Dendrites of one neuron receive signals from the axons of other neurons through chemicals known as neurotransmitters. The neurotransmitters set off electrical charges in the dendrites, which then carry the signals electrochemically to the soma. The soma integrates the information, which is then transmitted electrochemically down the axon to its tip.
At the tip of the axon, small, bubble-like structures called vesicles” release neurotransmitters that carry the signal across the synapse, or gap, between two neurons. There are many types of neurotransmitters, including norepinephrine, dopamine, and serotonin. Neurotransmitters can be excitatory (that is, they excite an electrochemical response in the dendrite receptors) or inhibitory (they block the response of the dendrite receptors).
One neuron may communicate with thousands of other neurons, and many thousands of neurons are involved with even the simplest behavior. It is believed that these connections and their efficiency can be modified, or altered, by experience.
Scientists have used two primary approaches to studying how the brain works. One approach is to study brain function after parts of the brain have been damaged. Functions that disappear or that is no longer normal after injury to specific regions of the brain can often be associated with the damaged areas. The second approach is to study the response of the brain to direct stimulation or to stimulation of various sense organs.
Neurons are grouped by function into collections of cells called nuclei. These nuclei are connected to form sensory, motor, and other systems. Scientists can study the function of somatosensory (pain and touch), motor, olfactory, visual, auditory, language, and other systems by measuring the physiological (physical and chemical) change that occur in the brain when these senses are activated. For example, electroencephalography (EEG) measures the electrical activity of specific groups of neurons through electrodes attached to the surface of the skull. Electrodes inserted directly into the brain can give readings of individual neurons. Changes in blood flow, glucose (sugar), or oxygen consumption in groups of active cells can also be mapped.
Although the brain appears symmetrical, how it functions is not. Each hemisphere is specializing and dominates the other in certain functions. Research has shown that hemispheric dominance is related to whether a person is predominantly right-handed or left-handed. In most right-handed people, the left hemisphere processes arithmetic, language, and speech. The right hemisphere interprets music, complex imagery, and spatial relationships and recognizes and expresses emotion. In left-handed people, the pattern of brain organization is more variable.
Hemispheric specialization has traditionally been studied in people who have sustained damage to the connections between the two hemispheres, as may occur with a stroke, an interruption of blood flow to an area of the brain that causes the death of nerve cells in that area. The division of functions between the two hemispheres has also been studied in people who have had to have the connection between the two hemispheres surgically cut in order to control severe epilepsy, a neurological disease characterized by convulsions and loss of consciousness.
The visual system of humans is one of the most advanced sensory systems in the body. More information is conveyed visually than by any other means. In addition to the structures of the eye itself, several cortical regions-collectively called primary visual and visual associative cortices-as well as the midbrain is involved in the visual system. Conscious processing of visual input occurs in the primary visual cortex, but reflexive-that is, immediate and unconscious-responses occur at the superior colliculus in the midbrain. Associative cortical regions-specialized regions that can associate, or integrate, multiple inputs-in the parietal and frontal lobes along with parts of the temporal lobe are also involved in the processing of visual information and the establishment of visual memories.
Language involves specialized cortical regions in a complex interaction that allows the brain to comprehend and communicate abstract ideas. The motor cortex initiates impulses that travel through the brain stem to produce audible sounds. Neighboring regions of motor cortices, called the supplemental motor cortex, are involved in sequencing and coordinating sounds. Broca's area of the frontal lobe is responsible for the sequencing of language elements for output. The comprehension of language is dependent upon Wernicke”s area of the temporal lobe. Other cortical circuits connect these areas.
Memory is usually considered a diffusely stored associative process-that is, it puts together information from many different sources. Although research has failed to identify specific sites in the brain as locations of individual memories, certain brain areas are critical for memory to function. Immediate recall-the ability to repeat short series of words or numbers immediately after hearing them-is thought to be located in the auditory associative cortex. Short-term memory-the ability to retain a limited amount of information for up to an hour-is located in the deep temporal lobe. Long-term memory probably involves exchanges between the medial temporal lobe, various cortical regions, and the midbrain.
The autonomic nervous system regulates the life support systems of the body reflexively-that is, without conscious direction. It automatically controls the muscles of the heart, digestive system, and lungs; certain glands; and homeostasis-that is, the equilibrium of the internal environment of the body. The autonomic nervous system itself is controlled by nerve centers in the spinal cord and brain stem and is fine-tuned by regions higher in the brain, such as the midbrain and cortex. Reactions such as blushing indicate that cognitive, or thinking, centers of the brain are also involved in autonomic responses.
The brain is guarded by several highly developed protective mechanisms. The bony cranium, the surrounding meninges, and the cerebrospinal fluid all contribute to the mechanical protection of the brain. In addition, a filtration system called the blood-brain barrier protects the brain from exposure to potentially harmful substances carried in the bloodstream. Brain disorders have a wide range of causes, including head injury, stroke, bacterial diseases, complex chemical imbalances, and changes associated with aging.
Head injury can initiate a cascade of damaging events. After a blow to the head, a person may be stunned or may become unconscious for a moment. This injury, called a concussion, usually leaves no permanent damage. If the blow is more severe and hemorrhage (excessive bleeding) and swelling occurs, however, severe headache, dizziness, paralysis, a convulsion, or temporary blindness may result, depending on the area of the brain affected. Damage to the cerebrum can also result in profound personality changes.
Damage to Broca”s area in the frontal lobe causes difficulty in speaking and writing, a problem known as Broca”s aphasia. Injury to Wernicke”s area in the left temporal lobe results in an inability to comprehend spoken language, called Wernicke's aphasia.
An injury or disturbance to a part of the hypothalamus may cause a variety of different symptoms, such as loss of appetite with an extreme drop in body weight; increase in appetite leading to obesity; extraordinary thirst with excessive urination (diabetes insipidus); failure in body-temperature control, resulting in either low temperature (hypothermia) or high temperature (fever); excessive emotionality; and uncontrolled anger or aggression. If the relationship between the hypothalamus and the pituitary gland is damaged, other vital bodily functions may be disturbed, such as sexual function, metabolism, and cardiovascular activity.
Injury to the brain stem is even more serious because it houses the nerve centers that control breathing and heart action. Damage to the medulla oblongata usually results in immediate death.
To the brain due to an interruption in blood flow. The interruption may be caused by a blood clot: constriction of a blood vessel, or rupture of a vessel accompanied by bleeding. A pouchlike expansion of the wall of a blood vessel, called an aneurysm, may weaken and burst, for example, because of high blood pressure.
Sufficient quantities of glucose and oxygen, transported through the bloodstream, are needed to keep nerve cells alive. When the blood supply to a small part of the brain is interrupted, the cells in that area die and the function of the area is lost. A massive stroke can cause a one-sided paralysis (hemiplegia) and sensory loss on the side of the body opposite the hemisphere damaged by the stroke.
Epilepsy is a broad term for a variety of brain disorders characterized by seizures, or convulsions. Epilepsy can result from a direct injury to the brain at birth or from a metabolic disturbance in the brain at any time later in life.
Some brain diseases, such as multiple sclerosis and Parkinson disease, are progressive, becoming worse over time. Multiple sclerosis damages the myelin sheath around axons in the brain and spinal cord. As a result, the affected axons cannot transmit nerve impulses properly. Parkinson disease destroys the cells of the substantia nigra in the midbrain, resulting in a deficiency in the neurotransmitter dopamine that affects motor functions.
Cerebral palsy is a broad term for brain damage sustained close to birth that permanently affects motor function. The damage may take place either in the developing fetus, during birth, or just after birth and is the result of the faulty development or breaking down of motor pathways. Cerebral palsy is nonprogressive-that is, it does not worsen with time.
A bacterial infection in the cerebrum or in the coverings of the brain swelling of the brain, or an abnormal growth of healthy brain tissue can all cause an increase in intracranial pressure and result in serious damage to the brain.
Scientists are finding that certain brain chemical imbalances are associated with mental disorders such as schizophrenia and depression. Such findings have changed scientific understanding of mental health and have resulted in new treatments that chemically correct these imbalances.
During childhood development, the brain is particularly susceptible to damage because of the rapid growth and reorganization of nerve connections. Problems that originate in the immature brain can appear as epilepsy or other brain-function problems in adulthood.
Several neurological problems are common in aging. Alzheimer”s disease damages many areas of the brain, including the frontal, temporal, and parietal lobes. The brain tissue of people with Alzheimer's disease shows characteristic patterns of damaged neurons, known as plaques and tangles. Alzheimer's disease produces a progressive dementia, characterized by symptoms such as failing attention and memory, loss of mathematical ability, irritability, and poor orientation in space and time.
Several commonly used diagnostic methods give images of the brain without invading the skull. Some portray anatomy-that is, the structure of the brain-whereas others measure brain function. Two or more methods may be used to complement each other, together providing a more complete picture than would be possible by one method alone.
Magnetic resonance imaging (MRI), introduced in the early 1980s, beams high-frequency radio waves into the brain in a highly magnetized field that causes the protons that form the nuclei of hydrogen atoms in the brain to remit the radio waves. The remitted radio waves are analyzed by computer to create thin cross-sectional images of the brain. MRI provides the most detailed images of the brain and is safer than imaging methods that use X rays. However, MRI is a lengthy process and also cannot be used with people who have pacemakers or metal implants, both of which are adversely affected by the magnetic field.
Computed tomography (CT), also known as CT scans, developed in the early 1970s. This imaging method X-rays the brain from many different angles, feeding the information into a computer that produces a series of cross-sectional images. CT is particularly useful for diagnosing blood clots and brain tumors. It is a much quicker process than magnetic resonance imaging and is therefore advantageous in certain situations-for example, with people who are extremely ill.
Changes in brain function due to brain disorders can be visualized in several ways. Magnetic resonance spectroscopy measures the concentration of specific chemical compounds in the brain that may change during specific behaviors. Functional magnetic resonance imaging (fMRI) maps changes in oxygen concentration that correspond to nerve cell activity.
Positron emission tomography (PET), developed in the mid-1970s, uses computed tomography to visualize radioactive tracers radioactive substances introduced into the brain intravenously or by inhalation. PET can measure such brain functions as cerebral metabolism, blood flow and volume, oxygen use, and the formation of neurotransmitters. Single photon emission computed tomography (SPECT), developed in the 1950s and 1960s, used radioactive tracers to visualize the circulation and volume of blood in the brain.
Brain-imaging studies have provided new insights into sensory, motor, language, and memory processes, as well as brain disorders such as epilepsy cerebrovascular disease; Alzheimer's, Parkinson, and Huntington”s diseases: And the various mental disorders, such as schizophrenia.
In lower vertebrates, such as fish and reptiles, the brain is often tubular and bears a striking resemblance to the early embryonic stages of the brains of more highly evolved animals. In all vertebrates, the brain is divided into three regions: the forebrain (prosencephalon), the midbrain (mesencephalon), and the hindbrain (rhombencephalon). These three regions further subdivide into different structures, systems, nuclei, and layers.
The more highly evolved the animal, the more complex is the brain structure. Human beings have the most complex brains of all animals. Evolutionary forces have also resulted in a progressive increase in the size of the brain. In vertebrates lower than mammals, the brain is small. In meat-eating animals, particularly primates, the brain increases dramatically in size.
The cerebrum and cerebellum of higher mammals are highly convoluted in order to fit the most gray matter surface within the confines of the cranium. Such highly convoluted brains are called gyrencephalic. Many lower mammals have a smooth, or lissencephalic (“smooth head”), cortical surfaces.
There is also evidence of evolutionary adaption of the brain. For example, many birds depend on an advanced visual system to identify food at great distances while in flight. Consequently, their optic lobes and cerebellum are well developed, giving them keen sight and outstanding motor coordination in flight. Rodents, on the other hand, as nocturnal animals, do not have a well-developed visual system. Instead, they rely more heavily on other sensory systems, such as a highly-developed sense of smell and facial whiskers.
Recent research in brain function suggests that there may be sexual differences in both brain anatomy and brain function. One study indicated that men and women may use their brains differently while thinking. Researchers used functional magnetic resonance imaging to observe which parts of the brain were activated as groups of men and women tried to determine whether sets of nonsense words rhymed. Men used only Broca”s area in this task, whereas women used Broca's area plus an area on the right side of the brain.
Both Analytic and Linguistic philosophy, are 20th-century philosophical movements, and dominate most of Britain and the United States since World War II, that aims to clarify language and analyze the concepts expressed in it. The movement has been given a variety of designations, including linguistic analysis, logical empiricism, logical positivism, Cambridge analysis, and “Oxford philosophy.” The last two labels are derived from the universities in England where this philosophical method has been particularly influential. Although no specific doctrines or tenets are accepted by the movement as a whole, analytic and linguistic philosophers agree that the proper activity of philosophy is clarifying language, or, as some prefer, clarifying concepts. The aim of this activity is to settle philosophical disputes and resolve philosophical problems, which, it is argued, originates in linguistic confusion.
A considerable diversity of views exists among analytic and linguistic philosophers regarding the nature of conceptual or linguistic analysis. Some have been primarily concerned with clarifying the meaning of specific words or phrases as an essential step in making philosophical assertions clear and unambiguous. Others have been more concerned with determining the general conditions that must be met for any linguistic utterance to be meaningful; their intent is to establish a criterion that will distinguish between meaningful and nonsensical sentences. Still other analysts have been interested in creating formal, symbolic languages that are mathematical in nature. Their claim is that philosophical problems can be more effectively dealt with once they are formulated in a rigorous logical language.
By contrast, many philosophers associated with the movement have focused on the analysis of ordinary, or natural, language. Difficulties arise when concepts such as time and freedom, for example, are considered apart from the linguistic context in which they normally appear. Attention to language as it is ordinarily used is the key, it is argued, to resolving many philosophical puzzles.
Many experts believe that philosophy as an intellectual discipline originated with the work of Plato, one of the most celebrated philosophers in history. The Greek thinker had an immeasurable influence on Western thought. However, Plato's expression of ideas in the form of dialogues-the dialectical method, used most famously by his teacher Socrates-has led to difficulties in interpreting some of the finer points of his thoughts. The issue of what exactly Plato meant to say is addressed in the following excerpt by author R. M. Hare.
Linguistic analysis as a method of philosophy is as old as the Greeks. Several of the dialogues of Plato, for example, are specifically concerned with clarifying terms and concepts. Nevertheless, this style of philosophizing has received dramatically renewed emphasis in the 20th century. Influenced by the earlier British empirical tradition of John Locke, George Berkeley, David Hume, and John Stuart Mill and by the writings of the German mathematician and philosopher Gottlob Frége, the 20th-century English philosopher's G. E. Moore and Bertrand Russell became the founders of this contemporary analytic and linguistic trend. As students together at the University of Cambridge, Moore and Russell rejected Hegelian idealism, particularly as it was reflected in the work of the English metaphysician F. H. Bradley, who held that nothing is completely real except the Absolute. In their opposition to idealism and in their commitment to the view that careful attention to language is crucial in philosophical inquiry. They set the mood and style of philosophizing for much of the 20th century English-speaking world.
For Moore, philosophy was first and foremost analysis. The philosophical task involves clarifying puzzling propositions or concepts by indicating less puzzling propositions or concepts to which the originals are held to be logically equivalent. Once this task has been completed, the truth or falsity of problematic philosophical assertions can be determined more adequately. Moore was noted for his careful analyses of such puzzling philosophical claims as “time is unreal,” analyses that then aided in determining the truth of such assertions.
Russell, strongly influenced by the precision of mathematics, was concerned with developing an ideal logical language that would accurately reflect the nature of the world. Complex propositions, Russell maintained, can be resolved into their simplest components, which he called atomic propositions. These propositions refer to atomic facts, the ultimate constituents of the universe. The metaphysical views based on this logical analysis of language and the insistence that meaningful propositions must correspond to facts constitute what Russell called logical atomism. His interest in the structure of language also led him to distinguish between the grammatical form of a proposition and its logical form. The statements “John is good” and “John is tall” have the same grammatical form but different logical forms. Failure to recognize this would lead one to treat the property “goodness” as if it were a characteristic of John in the same way that the property “tallness” is a characteristic of John. Such failure results in philosophical confusion.
Austrian-born philosopher Ludwig Wittgenstein was one of the most influential thinkers of the 20th century. With his fundamental work, Tractatus Logico-philosophicus, published in 1921, he became a central figure in the movement known as analytic and linguistic philosophy.
Russell”s work in mathematics attracted at Cambridge, the Austrian philosopher Ludwig Wittgenstein, who became a central figure in the analytic and linguistic movement. In his first major work, Tractatus Logico-philosophicus (1921, translated, 1922), in which he first presented his theory of language, Wittgenstein argued that “all philosophy is a “critique of language” ” and that “philosophy aims at the logical clarification of thoughts.” The results of Wittgenstein's analysis resembled Russell's logical atomism. The world, he argued, is ultimately composed of simple facts, which it is the purpose of language to picture. To be meaningful, statements about the world must be reducible to linguistic utterances that have a structure similar to the simple facts pictured. In this early Wittgensteinian analysis, only propositions that picture facts-the propositions of science-are considered factually meaningful. Metaphysical, theological, and ethical sentences were judged to be factually meaningless.
Influenced by Russell, Wittgenstein, Ernst Mach, and others, a group of philosophers and mathematicians in Vienna in the 1920s initiated the movement known as logical positivism: Led by Moritz Schlick and Rudolf Carnap, the Vienna Circle initiated one of the most important chapters in the history of analytic and linguistic philosophy. According to the positivist, the task of philosophy is the clarification of meaning, not the discovery of new facts (the job of the scientists) or the construction of comprehensive accounts of reality (the misguided pursuit of traditional metaphysics).
The positivist divided all meaningful assertions into two classes: analytic propositions and empirically verifiable ones. Analytic propositions, which include the propositions of logic and mathematics, are statements the truth or falsity of which depended altogether on the meanings of the terms constituting the statement. An example would be the proposition “two plus two equals four.” The second class of meaningful propositions includes all statements about the world that can be verified, at least in principle, by sense experience. Indeed, the meaning of such propositions is identified with the empirical method of their verification. This verifiability theory of meaning, the positivist concluded, would demonstrate that scientific statements are legitimate factual claims and that metaphysical, religious, and ethical sentences are factually empties. The ideas of logical positivism were made popular in England by the publication of A. J. Ayer”s Language, Truth and Logic in 1936.
The positivist” verifiability theory of meaning came under intense criticism by philosophers such as the Austrian-born British philosopher Karl Popper. Eventually this narrow theory of meaning yielded to a broader understanding of the nature of language. Again, an influential figure was Wittgenstein. Repudiating many of his earlier conclusions in the Tractatus, he initiated a new line of thought culminating in his posthumously published Philosophical Investigations (1953; translated, 1953). In this work, Wittgenstein argued that once attention is directed to the way language is actually used in ordinary discourse, the variety and flexibility of language become clear. Propositions do much more than simply picture facts.
This recognition led to Wittgenstein's influential concept of language games. The scientist, the poet, and the theologian, for example, are involved in different language games. Moreover, the meaning of a proposition must be understood in its context, that is, in terms of the rules of the language game of which that proposition is a part. Philosophy, concluded Wittgenstein, is an attempt to resolve problems that arise as the result of linguistic confusion, and the key to the resolution of such problems is ordinary language analysis and the proper use of language.
Additional contributions within the analytic and linguistic movement include the work of the British philosopher's Gilbert Ryle, John Austin, and P. F. Strawson and the American philosopher W. V. Quine. According to Ryle, the task of philosophy is to restate “systematically misleading expressions” in forms that are logically more accurate. He was particularly concerned with statements the grammatical form of which suggests the existence of nonexistent objects. For example, Ryle is best known for his analysis that has of a mental capacity of language, language that misleadingly suggests that the mind is an entity in the same way as the body.
Austin maintained that one of the most fruitful starting points for philosophical inquiry is attention to the extremely fine distinctions drawn in ordinary language. His analysis of language eventually led to a general theory of speech acts, that is, to a description of the variety of activities that an individual may be performing when something is uttered.
Strawson is known for his analysis of the relationship between formal logic and ordinary language. The complexity of the latter, he argued, is inadequately represented by formal logic. A variety of analytic tools, therefore, are needed in addition to logic in analyzing ordinary language.
Quine discussed the relationship between language and ontology. He argued that language systems tend to commit their users to the existence of certain things. For Quine, the justification for speaking one way rather than another is a thoroughly pragmatic one.
The commitment to language analysis as a way of pursuing philosophy has continued as a significant contemporary dimension in philosophy. A division also continues to exist between those who prefer to work with the precision and rigor of symbolic logical systems and those who prefer to analyze ordinary language. Although few contemporary philosophers maintain that all philosophical problems are linguistic, the view continues to be widely held that attention to the logical structure of language and to how language is used in everyday discourse can often aid in resolving philosophical problems.
A loose title for various philosophies that emphasize certain common themes, the individual, the experience of choice, and the absence of rational understandings of the universe, with a consequent dread or sense of “absurdity i9n human life” however, Existentialism is a philosophical movement or tendency, emphasizing individual existence, freedom, and choice, that influenced many diverse writers in the 19th and 20th centuries.
Because of the diversity of positions associated with existentialism, the term is impossible to define precisely. Certain themes common to virtually all existentialist writers can, however, be identified. The term itself suggests one major theme: the stress on concrete individual existence and, consequently, on subjectivity, individual freedom, and choice.
Most philosophers since Plato have held that the highest ethical good are the same for everyone; insofar as one approaches moral perfection, one resembles other morally perfect individuals. The 19th-century Danish philosopher Søren Kierkegaard, who was the first writer to call himself existential, reacted against this tradition by insisting that the highest good for the individual are to find his or her own unique vocation. As he wrote in his journal, “I must find a truth that is true for me . . . the idea for which I can live or die.” Other existentialist writers have echoed Kierkegaard”s belief that one must choose one's own way without the aid of universal, objective standards. Against the traditional view that moral choice involves an objective judgment of right and wrong, Existentialists have argued that no objective, rational basis can be found for moral decisions. The 19th-century German philosopher Friedrich Nietzsche further contended that the individual must decide which situations are to count as moral situations.
All Existentialists have followed Kierkegaard in stressing the importance of passionate individual action in deciding questions of both morality and truth. They have insisted, accordingly, that personal experience and acting on one's own convictions are essential in arriving at the truth. Thus, the understanding of a situation by someone involved in that situation is superior to that of a detached, objective observer. This emphasis on the perspective of the individual agent has also made Existentialists suspicious of systematic reasoning. Kierkegaard, Nietzsche, and other existentialist writers have been deliberately unsystematic in the exposition of their philosophies, preferring to express themselves in aphorisms, dialogues, parables, and other literary forms. Despite their antirationalist position, however, most Existentialists cannot be said to be irrationalists in the sense of denying all validity to rational thought. They have held that rational clarity is desirable wherever possible, but that the most important questions in life are not accessible to reason or science. Furthermore, they have argued that even science is not as rational as is commonly supposed. Nietzsche, for instance, asserted that the scientific assumption of an orderly universe is for the most part a useful fiction.
Perhaps the most prominent theme in existentialist writing is that of choice. Humanity's primary distinction, in the view of most Existentialists, is the freedom to choose. Existentialists have held that human beings do not have a fixed nature, or essence, as other animals and plants do; each human being makes choices that create his or her own nature. In the formulation of the 20th-century French philosopher Jean-Paul Sartre, existence precedes essence. Choice is therefore central to human existence, and it is inescapable; even the refusal to choose is a choice. Freedom of choice entails commitment and responsibility. Because individuals are free to choose their own path, Existentialists have argued, they must accept the risk and responsibility of following their commitment wherever it leads.
Kierkegaard held that it is spiritually crucial to recognize that one experiences not only a fear of specific objects but also a feeling of general apprehension, which he called dread. He interpreted it as God's way of calling each individual to make a commitment to a personally valid way of life. The word anxiety (German Angst) has a similarly crucial role in the work of the 20th-century German philosopher Martin Heidegger; anxiety leads to the individual”s confrontation with nothingness and with the impossibility of finding ultimate justification for the choices he or she must make. In the philosophy of Sartre, the word nausea is used for the individual”s recognition of the pure contingency of the universe, and the word anguish is used for the recognition of the total freedom of choice that confronts the individual at every moment.
Existentialism as a distinct philosophical and literary movement belongs to the 19th and 20th centuries, but elements of existentialism can be found in the thought (and life) of Socrates, in the Bible, and in the work of many premodern philosophers and writers.
The first to anticipate the major concerns of modern existentialism was the 17th-century French philosopher Blaise Pascal. Pascal rejected the rigorous rationalism of his contemporary René Descartes, asserting, in his Pensées (1670), that a systematic philosophy that presumes to explain God and humanity is a form of pride. Like later existentialist writers, he saw human life in terms of paradoxes: The human self, which combines mind and body, is itself a paradox and contradiction.
Kierkegaard, generally regarded as the founder of modern existentialism, reacted against the systematic absolute idealism of the 19th-century German philosopher Georg Wilhelm Friedrich Hegel, who claimed to have worked out a total rational understanding of humanity and history. Kierkegaard, on the contrary, stressed the ambiguity and absurdity of the human situation. The individual”s response to this situation must be to live a totally committed life, and this commitment can only be understood by the individual who has made it. The individual therefore must always be prepared to defy the norms of society for the sake of the higher authority of a personally valid way of life. Kierkegaard ultimately advocated a “leap of faith” into a Christian way of life, which, although incomprehensible and full of risk, was the only commitment he believed could save the individual from despair.
Danish religious philosopher Søren Kierkegaard rejected the all-encompassing, analytical philosophical systems of such 19th-century thinkers as German philosopher G. W. F. Hegel. Instead, Kierkegaard focused on the choices the individual must make in all aspects of his or her life, especially the choice to maintain religious faith. In Fear and Trembling (1846; trans. 1941), Kierkegaard explored the concept of faith through an examination of the biblical story of Abraham and Isaac, in which God demanded that Abraham demonstrate his faith by sacrificing his son.
One of the most controversial works of 19th-century philosophy, Thus Spake Zarathustra (1883-1885) articulated German philosopher Friedrich Nietzsche's theory of the Übermensch, a term translated as “Superman” or “Overman.” The Superman was an individual who overcame what Nietzsche termed the “slave morality” of traditional values, and lived according to his own morality. Nietzsche also advanced his idea that “God is dead,” or that traditional morality was no longer relevant in people”s lives. In this passage, the sage Zarathustra came down from the mountain where he had spent the last ten years alone to preach to the people.
Nietzsche, who was not acquainted with the work of Kierkegaard, influenced subsequent existentialist thought through his criticism of traditional metaphysical and moral assumptions and through his espousal of tragic pessimism and the life-affirming individual will that opposes itself to the moral conformity of the majority. In contrast to Kierkegaard, whose attack on conventional morality led him to advocate a radically individualistic Christianity, Nietzsche proclaimed the “death of God” and went on to reject the entire Judeo-Christian moral tradition in favor of a heroic pagan ideal.
The modern philosophy movements of phenomenology and existentialism have been greatly influenced by the thought of German philosopher Martin Heidegger. According to Heidegger, humankind has fallen into a crisis by taking a narrow, technological approach to the world and by ignoring the larger question of existence. People, if they wish to live authentically, must broaden their perspectives. Instead of taking their existence for granted, people should view themselves as part of Being (Heidegger's terms for that which underlies all existence).
Heidegger, like Pascal and Kierkegaard, reacted against an attempt to put philosophy on a conclusive rationalistic basis-in this case the phenomenology of the 20th-century German philosopher Edmund Husserl. Heidegger argued that humanity finds itself in an incomprehensible, indifferent world. Human beings can never hope to understand why they are here; instead, each individual must choose a goal and follow it with passionate conviction, aware of the certainty of death and the ultimate meaninglessness of one”s life. Heidegger contributed to existentialist thought an original emphasis on being and ontology (see Metaphysics) as well as on language.
Twentieth-century French intellectual Jean-Paul Sartre helped to develop existential philosophy through his writings, novels, and plays. Much of Sartre”s work focuses on the dilemma of choice faced by free individuals and on the challenge of creating meaning by acting responsibly in an indifferent world. In stating that “man is condemned to be free,” Sartre reminds us of the responsibility that accompanies human decisions.
Sartre first gave the term existentialism general currency by using it for his own philosophy and by becoming the leading figure of a distinct movement in France that became internationally influential after World War II. Sartre”s philosophy is explicitly atheistic and pessimistic; he declared that human beings require a rational basis for their lives but are unable to achieve one, and thus human life is a “futile passion.” Sartre nevertheless insisted that his existentialism is a form of humanism, and he strongly emphasized human freedom, choice, and responsibility. He eventually tried to reconcile these existentialist concepts with a Marxist analysis of society and history.
Although existentialist thought encompasses the uncompromising atheism of Nietzsche and Sartre and the agnosticism of Heidegger, its origin in the intensely religious philosophies of Pascal and Kierkegaard foreshadowed its profound influence on 20th-century theologies. The 20th-century German philosopher Karl Jaspers, although he rejected explicit religious doctrines, influenced a contemporary theology through his preoccupation with transcendence and the limits of human experience. The German Protestant theologian”s Paul Tillich and Rudolf Bultmann, the French Roman Catholic theologian Gabriel Marcel, the Russian Orthodox philosopher Nikolay Berdyayev, and the German Jewish philosopher Martin Buber inherited many of Kierkegaard's concerns, especially that a personal sense of authenticity and commitment is essential to religious faith.
Renowned as one of the most important writers in world history, 19th-century Russian author Fyodor Dostoyevsky wrote psychologically intense novels which probed the motivations and moral justifications for his characters” actions. Dostoyevsky commonly addressed themes such as the struggle between good and evil within the human soul and the idea of salvation through suffering. The Brothers Karamazov (1879-1880), generally considered Dostoyevsky's best work, interlaces religious exploration with the story of a family's violent quarrels over a woman and a disputed inheritance.
Also, Maurice Merleau-Ponty (1908-1961), the French existentialist philosopher, whose phenomenological studies of the role of the body in perception and society opened a new field of philosophical investigation. He taught at the University of Lyon, at the Sorbonne, and, after 1952, at the Collège de France. His first important work was The Structure of Comportment (1942; trans. 1963), a critique of behaviorism. His major work, Phenomenology of Perception (1945; trans. 1962), is a detailed study of perception, influenced by the German philosopher Edmund Husserl”s phenomenology and by Gestalt psychology. In it, he argues that science presupposes an original and unique perceptual relation to the world that cannot be explained or even described in scientific terms. This book can be viewed as a critique of cognitivism-the view that the working of the human mind can be understood in terms of rules or programs. It is also a telling critique of the existentialism of his contemporary, Jean-Paul Sartre, showing how human freedom is never total, as Sartre claimed, but is limited by our embodiment.
With Sartre and Simone de Beauvoir, Merleau-Ponty founded an influential postwar French journal, Les Temps Modernes. His brilliant and timely essays on art, film, politics, psychology, and religion, first published in this journal, were later collected in Sense and Nonsense (1948; trans. 1964). At the time of his death, he was working on a book, The Visible and the Invisible (1964; trans. 1968), arguing that the whole perceptual world has the sort of organic unity he had earlier.
A number of existentialist philosophers used literary forms to convey their thought, and existentialism has been as vital and as extensive a movement in literature as in philosophy. The 19th-century Russian novelist Fyodor Dostoyevsky is probably the greatest existentialist literary figure. In Notes from the Underground (1864), the alienated antihero rages against the optimistic assumptions of rationalist humanism. The view of human nature that emerges in this and other novels of Dostoyevsky is that it is unpredictable and perversely self-destructive; only Christian love can save humanity from itself, but such love cannot be understood philosophically. As the character Alyosha says in The Brothers Karamazov (1879-80), “We must love life more than the meaning of it.”
The opening lines of Russian novelist Fyodor Dostoyevsky's Notes from Underground (1864)-“I am a sick man . . . I am a spiteful man”-are among the most famous in 19th-century literature. Published five years after his release from prison and involuntary, military service in Siberia, Notes from Underground is a sign of Dostoyevsky's rejection of the radical social thinking he had embraced in his youth. The unnamed narrator is antagonistic in tone, questioning the reader”s sense of morality as well as the foundations of rational thinking. In this excerpt from the beginning of the novel, the narrator describes himself, derisively referring to himself as an “overly conscious” intellectual.
In the 20th century, the novels of the Austrian Jewish writer Franz Kafka, such as The Trial (1925; trans. 1937) and The Castle (1926; trans. 1930), present isolated men confronting vast, elusive, menacing bureaucracies; Kafka”s themes of anxiety, guilt, and solitude reflect the influence of Kierkegaard, Dostoyevsky, and Nietzsche. The influence of Nietzsche is also discernible in the novels of the French writer”s André Malraux and in the plays of Sartre. The work of the French writer Albert Camus is usually associated with existentialism because of the prominence in it of such themes as the apparent absurdity and futility of life, the indifference of the universe, and the necessity of engagement in a just cause. Existentialist themes are also reflected in the theater of the absurd, notably in the plays of Samuel Beckett and Eugène Ionesco. In the United States, the influence of existentialism on literature has been more indirect and diffuse, but traces of Kierkegaard”s thought can be found in the novels of Walker Percy and John Updike, and various existentialist themes are apparent in the work of such diverse writers as Norman Mailer, John Barth, and Arthur
The problem of defining knowledge in terms of true belief plus some favoured relation between the believer and the facts began with Plato”s view in the Theaetetus, that knowledge is true belief plus some logos, an epistemology is to begin of holding the Foundations of knowledge, a special branches of philosophy that addresses the philosophical problems surrounding the theory of knowledge. Epistemology is concerned with the definition of knowledge and related concepts, the sources and criteria of knowledge, the kinds of knowledge possible and the degree to which each is certain, and the exact relation among the one who knows and the object known.
Thirteenth-century Italian philosopher and theologian Saint Thomas Aquinas attempted to synthesize Christian belief with a broad range of human knowledge, embracing diverse sources such as Greek philosopher Aristotle and Islamic and Jewish scholars. His thought exerted lasting influence on the development of Christian theology and Western philosophy. Author Anthony Kenny examines the complexities of Aquinas”s concepts of substance and accident.
In the 5th century Bc, the Greek Sophists questioned the possibility of reliable and objective knowledge. Thus, a leading Sophist, Gorgias, argued that nothing really exists, that if anything did exist it could not be known, and that if knowledge were possible, it could not be communicated. Another prominent Sophist, Protagoras, maintained that no person”s opinions can be said to be more correct than another”s, because each is the sole judge of his or her own experience. Plato, following his illustrious teacher Socrates, tried to answer the Sophists by postulating the existence of a world of unchanging and invisible forms, or ideas, about which it is possible to have exact and certain knowledge. The thing”s one sees and touches, they maintained, are imperfect copies of the pure forms studied in mathematics and philosophy. Accordingly, only the abstract reasoning of these disciplines yields genuine knowledge, whereas reliance on sense perception produces vague and inconsistent opinions. They concluded that philosophical contemplation of the unseen world of forms is the highest goal of human life.
Aristotle followed Plato in regarding abstract knowledge as superior to any other, but disagreed with him as to the proper method of achieving it. Aristotle maintained that almost all knowledge is derived from experience. Knowledge is gained either directly, by abstracting the defining traits of a species, or indirectly, by deducing new facts from those already known, in accordance with the rules of logic. Careful observation and strict adherence to the rules of logic, which were first set down in systematic form by Aristotle, would help guard against the pitfalls the Sophists had exposed. The Stoic and Epicurean schools agreed with Aristotle that knowledge originates in sense perception, but against both Aristotle and Plato they maintained that philosophy is to be valued as a practical guide to life, rather than as an end in itself.
After many centuries of declining interest in rational and scientific knowledge, the Scholastic philosopher Saint Thomas Aquinas and other philosophers of the Middle Ages helped to restore confidence in reason and experience, blending rational methods with faith into a unified system of beliefs. Aquinas followed Aristotle in regarding perception as the starting point and logic as the intellectual procedure for arriving at reliable knowledge of nature, but he considered faith in scriptural authority as the main source of religious belief.
From the 17th to the late 19th century, the main issue in epistemology was reasoning versus sense perception in acquiring knowledge. For the rationalists, of whom the French philosopher René Descartes, the Dutch philosopher Baruch Spinoza, and the German philosopher Gottfried Wilhelm Leibniz were the leaders, the main source and final test of knowledge was deductive reasoning based on self-evident principles, or axioms. For the empiricist, beginning with the English philosophers Francis Bacon and John Locke, the main source and final test of knowledge was sense perception.
Bacon inaugurated the new era of modern science by criticizing the medieval reliance on tradition and authority and also by setting down new rules of scientific method, including the first set of rules of inductive logic ever formulated. Locke attacked the rationalist belief that the principles of knowledge are intuitively self-evident, arguing that all knowledge is derived from experience, either from experience of the external world, which stamps sensations on the mind, or from internal experience, in which the mind reflects on its own activities. Human knowledge of external physical objects, he claimed, is always subject to the errors of the senses, and he concluded that one cannot have absolutely certain knowledge of the physical world.
Irish-born philosopher and clergyman George Berkeley (1685-1753) argued that everything that human being conceived of exists as an idea in a mind, a philosophical focus which is known as idealism. Berkeley reasoned that because one cannot control one”s thoughts, they must come directly from a larger mind: that of God. In this excerpt from his Treatise Concerning the Principles of Human Knowledge, written in 1710, Berkeley explained why he believed that it is “impossible . . . that there should be any such thing as an outward object.”
The Irish philosopher George Berkeley agreed with Locke, that knowledge comes through ideas, but he denied Locke”s belief that a distinction can be made between ideas and objects. The British philosopher David Hume continued the empiricist tradition, but he did not accept Berkeley”s conclusion that knowledge was of ideas only. He divided all knowledge into two kinds: knowledge of relations of ideas-that is, the knowledge found in mathematics and logic, which is exact and certain but provide no information about the world; and knowledge of matters of fact-that is, the knowledge derived from sense perception. Hume argued that most knowledge of matters of fact depends upon cause and effect, and since no logical connection exists between any given cause and its effect, one cannot hope to know any future matter of fact with certainty. Thus, the most reliable laws of science might not remain true-a conclusion that had a revolutionary impact on philosophy.
The German philosopher Immanuel Kant tried to solve the crisis precipitated by Locke and brought to a climax by Hume; his proposed solution combined elements of rationalism with elements of empiricism. He agreed with the rationalists that one can have exact and certain knowledge, but he followed the empiricist in holding that such knowledge is more informative about the structure of thought than about the world outside of thought. He distinguished three kinds of knowledge: analytical a priori, which is exact and certain but uninformative, because it makes clear only what is contained in definitions; synthetic a posteriori, which conveys information about the world learned from experience, but is subject to the errors of the senses; and synthetic a priori, which is discovered by pure intuition and is both exact and certain, for it expresses the necessary conditions that the mind imposes on all objects of experience. Mathematics and philosophy, according to Kant, provide this last. Since the time of Kant, one of the most frequently argued questions in philosophy has been whether or not such a thing as synthetic a priori knowledge really exists.
During the 19th century, the German philosopher Georg Wilhelm Friedrich Hegel revived the rationalist claim that absolutely certain knowledge of reality can be obtained by equating the processes of thought, of nature, and of history. Hegel inspired an interest in history and a historical approach to knowledge that was further emphasized by Herbert Spencer in Britain and by the German school of historicism. Spencer and the French philosopher Auguste Comte brought attention to the importance of sociology as a branch of knowledge, and both extended the principles of empiricism to the study of society.
The American school of pragmatism, founded by the philosophers Charles Sanders Peirce, William James, and John Dewey at the turn of this century, carried empiricism further by maintaining that knowledge is an instrument of action and that all beliefs should be judged by their usefulness as rules for predicting experiences.
In the early 20th century, epistemological problems were discussed thoroughly, and subtle shades of difference grew into rival schools of thought. Special attention was given to the relation between the act of perceiving something, the object directly perceived, and the thing that can be said to be known as a result of the perception. The phenomenalists contended that the objects of knowledge are the same as the objects perceived. The neorealists argued that one has direct perceptions of physical objects or parts of physical objects, rather than of one's own mental states. The critical realists took a middle position, holding that although one perceives only sensory data such as colors and sounds, these stand for physical objects and provide knowledge thereof.
A method for dealing with the problem of clarifying the relation between the act of knowing and the object known was developed by the German philosopher Edmund Husserl. He outlined an elaborate procedure that he called phenomenology, by which one is said to be able to distinguish the way things appear to be from the way one thinks they really are, thus gaining a more precise understanding of the conceptual foundations of knowledge.
Scientific knowledge reveals that scientific knowledge and method did not spring full-blown from the minds of the ancient Greeks any more than language and culture emerged fully in the minds of Homo sapiens sapient. Scientific knowledge is an extension of ordinary language into greater levels of abstraction and precision through reliance upon geometric and numerical relationships. We speculate that the seeds of the scientific imagination were planted in ancient Greece, as opposed to Chinese or Babylonian culture, partly because the social, political and economic climate in Greece was more open because the social, political, and economic climate in Greece was more open to the pursuit of knowledge with marginal cultural utility. Another important factor was that the special character of Homeric religion allowed the Greeks to invent a conceptual framework that would prove useful in future scientific investigations, but it was only after this inheritance from Greek philosophy was wed to some essential features of Judeo-Christian beliefs about the origin of the cosmos that the paradigm for classical physics emerged.
During the second quarter of the 20th century, two schools of thought emerged, each indebted to the Austrian philosopher Ludwig Wittgenstein. The first of these schools, logical empiricism, or logical positivism, had its origins in Vienna, Austria, but it soon spread to England and the United States. The logical empiricist insisted that there is only one kind of knowledge: scientific knowledge; that any valid knowledge claim must be verifiable in experience; and hence that much that had passed for philosophy was neither true nor false but literally meaningless. Finally, following Hume and Kant, a clear distinction must be maintained between analytic and synthetic statements. The so-called verifiability criterion of meaning has undergone changes as a result of discussions among the logical empiricist themselves, as well as their critics, but has not been discarded. More recently, the sharp distinction between the Analytic and the synthetic has been attacked by a number of philosophers, chiefly by American philosopher W.V.O. Quine, whose overall approach is in the pragmatic tradition.
The latter of these recent schools of thought, generally referred to as linguistic analysis, or ordinary language philosophy, seem to break with traditional epistemology. The linguistic analysts undertake to examine the actual way key epistemological terms are used-terms such as knowledge, perception, and probability-and to formulate definitive rules for their use in order to avoid verbal confusion. British philosopher John Langshaw Austin argued, for example, that to say a statement was truly added but nothing to the statement except a promise by the speaker or writer. Austin does not consider truth a quality or property attaching to statements or utterances. However, the ruling thought is that it is only through a correct appreciation of the role and point of this language that we can come to a better conception of what the language is about, and avoid the oversimplifications and distortion we are apt to bring to its subject matter.
Linguistics is the scientific study of language. It encompasses the description of languages, the study of their origin, and the analysis of how children acquire language and how people learn languages other than their own. Linguistics is also concerned with relationships between languages and with the ways languages change over time. Linguists may study language as a thought process and seek a theory that accounts for the universal human capacity to produce and understand language. Some linguists examine language within a cultural context. By observing talk, they try to determine what a person needs to know in order to speak appropriately in different settings, such as the workplace, among friends, or among family. Other linguists focus on what happens when speakers from different language and cultural backgrounds interact. Linguists may also concentrate on how to help people learn another language, using what they know about the learner”s first language and about the language being acquired.
Although there are many ways of studying language, most approaches belong to one of the two main branches of linguistics: descriptive linguistics and comparative linguistics.
Descriptive linguistics is the study and analysis of spoken language. The techniques of descriptive linguistics were devised by German American anthropologist Franz Boas and American linguist and anthropologist Edward Sapir in the early 1900s to record and analyze Native American languages. Descriptive linguistics begins with what a linguist hears native speakers say. By listening to native speakers, the linguist gathered a body of data and analyzed it in order to identify distinctive sounds, called phonemes. Individual phonemes, such as /p/ and /b/, are established on the grounds that substitution of one for the other changes the meaning of a word. After identifying the entire inventory of sounds in a language, the linguist looks at how these sounds combine to create morphemes, or units of sound that carry meaning, such as the words push and bush. Morphemes may be individual words such as push; root words, such as a berry in blueberry; or prefixes (pre-in preview) and suffixes (-ness in openness).
The linguist”s next step is to see how morphemes combine into sentences, obeying both the dictionary meaning of the morpheme and the grammatical rules of the sentence. In the sentence “She pushed the bush,” the morpheme she, a pronoun, is the subject; push, a transitive verb, is the verb “the”, a definite article, is the determiner; and bush, a noun, is the object. Knowing the function of the morphemes in the sentence enables the linguist to describe the grammar of the language. The scientific procedures of phonemics (finding phonemes), morphology (discovering morphemes), and syntaxes (describing the order of morphemes and their function) provided descriptive linguists with a way to write down grammars of languages never before written down or analyzed. In this way they can begin to study and understand these languages.
Comparative linguistics is the study and analysis, by means of written records, of the origins and relatedness of different languages. In 1786 Sir William Jones, a British scholar, asserted that Sanskrit, Greek, and Latin was related to one another and had descended from a common source. He based this assertion on observations of similarities in sounds and meanings among the three languages. For example, the Sanskrit word bhratar for “brother” resembles the Latin word frater, the Greek word phrater, (and the English word brother).
Other scholars went on to compare Icelandic with Scandinavian languages, and Germanic languages with Sanskrit, Greek, and Latin. The correspondences among languages, known as genetic relationships, came to be represented on what comparative linguists refer to as family trees. Family trees established by comparative linguists include the Indo-European, relating Sanskrit, Greek, Latin, German, English, and other Asian and European languages; the Algonquian, relating Fox, Cree, Menomini, Ojibwa, and other Native North American languages; and the Bantu, relating Swahili, Xhosa, Zulu, Kikuyu, and other African languages.
Comparative linguists also look for similarities in the way words are formed in different languages. Latin and English, for example, change the form of a word to express different meanings, as when the English verb goes interchangeably to go and gone, only to express a past action. Chinese, on the other hand, has no such inflected forms; the verb remains the same while other words indicate the time (as, in “go store tomorrow”). In Swahili, prefixes, suffixes, and infixes (additions in the body of the word) combine with a root word to change its meaning. For example, a single word might expressibly go when something was done, by whom, to whom, and in what manner.
Some comparative linguists reconstruct hypothetical ancestral languages known as proto-languages, which they use to demonstrate relatedness among contemporary languages. A proto-language is not intended to depict a real language, however, and does not represent the speech of ancestors of people speaking modern languages. Unfortunately, some groups have mistakenly used such reconstructions in efforts to demonstrate the ancestral homeland of those people.
Comparative linguists have suggested that certain basic words in a language do not change over time, because people are reluctant to introduce new words for such constants as arm, eye, or mother. These words are termed culture free. By comparing lists of culture-free words in languages within a family, linguists can derive the percentage of related words and use a formula to figure out when the languages separated from one another.
By the 1960s comparativists were no longer satisfied with focusing on origins, migrations, and the family tree method. They challenged as unrealistic the notion that an earlier language could remain sufficiently isolated for other languages to be derived exclusively from it over a period of time. Today comparativists seek to understand the more complicated reality of language history, taking language contact into account. They are concerned with universal characteristics of language and with comparisons of grammars and structures.
The field of linguistics both borrows from and lends its own theories and methods to other disciplines. The many subfields of linguistics have expanded our understanding of languages. Linguistic theories and methods are also used in other fields of study. These overlapping interests have led to the creation of several cross-disciplinary fields.
Sociolinguistics are the study of patterns and variations in language within a society or community. It focuses on the way people use language to express social class, group status, gender, or ethnicity, and it looks at how they make choices about the form of language they use. It also examines the way people use language to negotiate their role in society and to achieve positions of power. For example, sociolinguistic studies have found that the way a New Yorker pronounces the phoneme /r/ in an expression such as “fourth floor” can indicate the person”s social class. According to one study, people aspiring to move from the lower middle classes to the upper middle class attach prestige to pronouncing the /r/. Sometimes they even overcorrect their speech, pronouncing a /r/ where those whom they wish to copy may not.
Some sociolinguists believe that analyzing such variables as the use of a particular phoneme can predict the direction of language change. Change, they say, moves toward the variable associated with power, prestige, or other quality having high social value. Other sociolinguists focus on what happens when speakers of different languages interact. This approach to language change emphasizes the way languages mix rather than the direction of change within a community. The goal of Sociolinguistics is to understand communicative competence-what people need to know to use the appropriate language for a given social setting.
Psycholinguistics merge the fields of psychology and linguistics to study how people process language and how language use is related to underlying mental processes. Studies of children”s language acquisition and of second-language acquisition are psycholinguistic in nature. Psycholinguists work to develop models for how language is processed and understood, using evidence from studies of what happens when these processes go awry. They also study language disorders such as aphasia (impairment of the ability to use or comprehend words) and dyslexia (impairment of the ability to make out written language).
Computational linguistics involves the use of computers to compile linguistic data, analyze languages, translate from one language to another, and develop and test models of language processing. Linguists use computers and large samples of actual language to analyze the relatedness and the structure of languages and to look for patterns and similarities. Computers also aid in stylistic studies, information retrieval, various forms of textual analysis, and the construction of dictionaries and concordances. Applying computers to language studies has resulted in machine translation systems and machines that recognize and produce speech and text. Such machines facilitate communication with humans, including those who are perceptually or linguistically impaired.
Applied linguistics employs linguistic theory and methods in teaching and in research on learning a second language. Linguists look at the errors people make as they learn another language and at their strategies for communicating in the new language at different degrees of competence. In seeking to understand what happens in the mind of the learner, applied linguists recognize that motivation, attitude, learning style, and personality affect how well a person learns another language.
Anthropological linguistics, also known as linguistic anthropology, uses linguistic approaches to analyze culture. Anthropological linguists examine the relationship between a culture and its language. The way cultures and languages have changed over time, and how different cultures and languages are related to one another. For example, the present English use of family and given names arose in the late 13th and early 14th centuries when the laws concerning registration, tenure, and inheritance of property were changed.
Philosophical linguistics examines the philosophy of language. Philosophers of language search for the grammatical principles and tendencies that all human languages share. Among the concerns of linguistic philosophers is the range of possible word order combinations throughout the world. One finding is that 95 percent of the world's languages use a subject-verb-object (SVO) order as English does (“She pushed the bush.”). Only 5 percent use a subject-object-verb (SOV) order or verb-subject-object (VSO) order.
Neurolinguistics are the study of how language is processed and represented in the brain. Neurolinguists seek to identify the parts of the brain involved with the production and understanding of language and to determine where the components of language (phonemes, morphemes, and structure or syntax) are stored. In doing so, they make use of techniques for analyzing the structure of the brain and the effects of brain damage on language.
Speculation about language goes back thousands of years. Ancient Greek philosophers speculated on the origins of language and the relationship between objects and their names. They also discussed the rules that govern language, or grammar, and by the 3rd century Bc they had begun grouping words into parts of speech and devising names for different forms of verbs and nouns.
In India religion provided the motivation for the study of language nearly 2500 years ago. Hindu priests noted that the language they spoke had changed since the compilation of their ancient sacred texts, the Vedas, starting about 1000 Bc. They believed that for certain religious ceremonies based upon the Vedas to succeed, they needed to reproduce the language of the Vedas precisely. Panini, an Indian grammarian who lived about 400 Bc, produced the earliest work describing the rules of Sanskrit, the ancient language of India.
The Romans used Greek grammars as models for their own, adding commentary on Latin style and usage. Statesman and orator Marcus Tullius Cicero wrote on rhetoric and style in the 1st century Bc. Later grammarian’s Aelius Donatus (4th century ad) and Priscian (6th century ad) produced detailed Latin grammars. Roman works served as textbooks and standards for the study of language for more than 1000 years.
It was not until the end of the 18th century that language was researched and studied in a scientific way. During the 17th and 18th centuries, modern languages, such as French and English, replaced Latin as the means of universal communication in the West. This occurrence, along with developments in printing, meant that many more texts became available. At about this time, the study of phonetics, or the sounds of a language, began. Such investigations led to comparisons of sounds in different languages; in the late 18th century the observation of correspondences among Sanskrit, Latin, and Greek gave birth to the field of Indo-European linguistics.
During the 19th century, European linguists focused on philology, or the historical analysis and comparison of languages. They studied written texts and looked for changes over time or for relationships between one language and another.
American linguist, writer, teacher, and political activist Noam Chomsky is considered the founder of transformational-generative linguistic analysis, which revolutionized the field of linguistics. This system of linguistics treats grammar as a theory of language-that is, Chomsky believes that in addition to the rules of grammar specific to individual languages, there are universal rules common to all languages that indicate that the ability to form and understand language is innate to all human beings. Chomsky also is well known for his political activism-he opposed United States involvement in Vietnam in the 1960s and 1970s and has written various books and articles and delivered many lectures in an attempt to educate and empower people on various political and social issues.
In the early 20th century, linguistics expanded to include the study of unwritten languages. In the United States linguists and anthropologists began to study the rapidly disappearing spoken languages of Native North Americans. Because many of these languages were unwritten, researchers could not use historical analysis in their studies. In their pioneering research on these languages, anthropologist’s Franz Boas and Edward Sapir developed the techniques of descriptive linguistics and theorized on the ways in which language shapes our perceptions of the world.
An important outgrowth of descriptive linguistics is a theory known as structuralism, which assumes that language is a system with a highly organized structure. Structuralism began with publication of the work of Swiss linguist Ferdinand de Saussure in Cours de linguistique générale (1916; Course in General Linguistics, 1959). This work, compiled by Saussure”s students after his death, is considered the foundation of the modern field of linguistics. Saussure made a distinction between actual speech, or spoken language, and the knowledge underlying speech that speakers share about what is grammatical. Speech, he said, represents instances of grammar, and the linguist”s task is to find the underlying rules of a particular language from examples found in speech. To the Structuralists, grammar is a set of relationships that account for speech, rather than a set of instances of speech, as it is to the descriptivist.
Once linguists began to study language as a set of abstract rules that somehow account for speech, other scholars began to take an interest in the field. They drew analogies between language and other forms of human behavior, based on the belief that a shared structure underlies many aspects of a culture. Anthropologists, for example, became interested in a Structuralists approach to the interpretation of kinship systems and analysis of myth and religion. American linguist Leonard Bloomfield promoted structuralism in the United States.
Saussure”s ideas also influenced European linguistics, most notably in France and Czechoslovakia (now the Czech Republic). In 1926 Czech linguist Vilem Mathesius founded the Linguistic Circle of Prague, a group that expanded the focus of the field to include the context of language use. The Prague circle developed the field of phonology, or the study of sounds, and demonstrated that universal features of sounds in the languages of the world interrelate in a systematic way. Linguistic analysis, they said, should focus on the distinctiveness of sounds rather than on the ways they combine. Where descriptivists tried to locate and describe individual phonemes, such as /b/ and /p/, the Prague linguists stressed the features of these phonemes and their interrelationships in different languages. In English, for example, the voice distinguishes between the similar sounds of /b/ and /p/, but these are not distinct phonemes in a number of other languages. An Arabic speaker might pronounce the cities Pompei and Bombay the same way.
As linguistics developed in the 20th century, the notion became prevalent that language is more than speech-specifically, that it is an abstract system of interrelationships shared by members of a speech community. Structural linguistics led linguists to look at the rules and the patterns of behavior shared by such communities. Whereas structural linguists saw the basis of language in the social structure, other linguists looked at language as a mental process.
The 1957 publication of Syntactic Structures by American linguist Noam Chomsky initiated what many view as a scientific revolution in linguistics. Chomsky sought a theory that would account for both linguistic structure and the creativity of language-the fact that we can create entirely original sentences and understand sentences never before uttered. He proposed that all people have an innate ability to acquire language. The task of the linguist, he claimed, is to describe this universal human ability, known as language competence, with a grammar from which the grammars of all languages could be derived. The linguist would develop this grammar by looking at the rules children use in hearing and speaking their first language. He termed the resulting model, or grammar, a transformational-generative grammar, referring to the transformations (or rules) that generate (or account for) language. Certain rules, Chomsky asserted, are shared by all languages and form part of a universal grammar, while others are language specific and associated with particular speech communities. Since the 1960s much of the development in the field of linguistics has been a reaction to or against Chomsky”s theories.
At the end of the 20th century, linguists used the term grammar primarily to refer to a subconscious linguistic system that enables people to produce and comprehend an unlimited number of utterances. Grammar thus accounts for our linguistic competence. Observations about the actual language we use, or language performance, are used to theorize about this invisible mechanism known as grammar.
The orientation toward the scientific study of language led by Chomsky has had an impact on nongenerative linguists as well. Comparative and historically oriented linguists are looking for the various ways linguistic universals show up in individual languages. Psycholinguists, interested in language acquisition, are investigating the notion that an ideal speaker-hearer is the origin of the acquisition process. Sociolinguists are examining the rules that underlie the choice of language variants, or codes, and allow for switching from one code to another. Some linguists are studying language performance-the way people use language-see how it reveals a cognitive ability shared by all human beings. Others seek to understand animal communication within such a framework. What mental processes enable chimpanzees to make signs and communicate with one another and how do these processes differ from those of humans?
A written bibliographic note in gratification To Ludwig Wittgenstein (1889-1951), an Austrian-British philosopher, who was one of the most influential thinkers of the 20th century, particularly noted for his contribution to the movement known as analytic and linguistic philosophy.
Born in Vienna on April 26, 1889, Wittgenstein was raised in a wealthy and cultured family. After attending schools in Linz and Berlin, he went to England to study engineering at the University of Manchester. His interest in pure mathematics led him to Trinity College, University of Cambridge, to study with Bertrand Russell. There he turned his attention to philosophy. By 1918 Wittgenstein had completed his Tractatus Logico-philosophicus (1921; trans. 1922), a work he then believed provided the “final solution” to philosophical problems. Subsequently, he turned from philosophy and for several years taught elementary school in an Austrian village. In 1929 he returned to Cambridge to resume his work in philosophy and was appointed to the faculty of Trinity College. Soon he began to reject certain conclusions of the Tractatus and to develop the position reflected in his Philosophical Investigations (pub. posthumously 1953; trans. 1953). Wittgenstein retired in 1947; he died in Cambridge on April 29, 1951. A sensitive, intense man who often sought solitude and was frequently depressed, Wittgenstein abhorred pretense and was noted for his simple style of life and dress. The philosopher was forceful and confident in personality, however, and he exerted considerable influence on those with whom he came in contact.
Wittgenstein”s philosophical life may be divided into two distinct phases: an early period, represented by the Tractatus, and a later period, represented by the Philosophical Investigations. Throughout most of his life, however, Wittgenstein consistently viewed philosophy as linguistic or conceptual analysis. In the Tractatus he argued that “philosophy aims at the logical clarification of thoughts.” In the Philosophical Investigations, however, he maintained that “philosophy is a battle against the bewitchment of our intelligence by means of language.”
Language, Wittgenstein argued in the Tractatus, is composed of complex propositions that can be analyzed into fewer complex propositions until one arrives at simple or elementary propositions. Correspondingly, the world is composed of complex facts that can be analyzed into fewer complex facts until one arrives at simple, or atomic, facts. The world is the totality of these facts. According to Wittgenstein”s picture theory of meaning, it is the nature of elementary propositions logically to picture atomic facts, or “states of affairs.” He claimed that the nature of language required elementary propositions, and his theory of meaning required that there be atomic facts pictured by the elementary propositions. On this analysis, only propositions that picture facts-the propositions of science-are considered cognitively meaningfully. Metaphysical and ethical statements are not meaningful assertions. The logical positivist associated with the Vienna Circle were greatly influenced by this conclusion.
Wittgenstein came to believe, however, that the narrow view of language reflected in the Tractatus was mistaken. In the Philosophical Investigations he argued that if one actually looks to see how language is used, the variety of linguistic usage becomes clear. Words are like tools, and just as tools serve different functions, so linguistic expressions serve many functions. Although some propositions are used to picture facts, others are used to command, question, pray, thank, curse, and so on. This recognition of linguistic flexibility and variety led to Wittgenstein”s concept of a language game and to the conclusion that people play different language games. The scientist, for example, is involved in a different language game than the theologian. Moreover, the meaning of a proposition must be understood in terms of its context, that is, in terms of the rules of the game of which that proposition is a part. The key to the resolution of philosophical puzzles is the therapeutic process of examining and describing language in use.
Analytic and Linguistic Philosophy, is a product out of the 20th-century philosophical movement, and dominant in Britain and the United States since World War II, that aims to clarify language and analyze the concepts expressed in it. The movement has been given a variety of designations, including linguistic analysis, logical empiricism, logical positivism, Cambridge analysis, and “Oxford philosophy.” The last two labels are derived from the universities in England where this philosophical method has been particularly influential. Although no specific doctrines or tenets are accepted by the movement as a whole, analytic and linguistic philosophers agree that the proper activity of philosophy is clarifying language, or, as some prefer, clarifying concepts. The aim of this activity is to settle philosophical disputes and resolve philosophical problems, which, it is argued, originates in linguistic confusion.
A considerable diversity of views exists among analytic and linguistic philosophers regarding the nature of conceptual or linguistic analysis. Some have been primarily concerned with clarifying the meaning of specific words or phrases as an essential step in making philosophical assertions clear and unambiguous. Others have been more concerned with determining the general conditions that must be met for any linguistic utterance to be meaningful; their intent is to establish a criterion that will distinguish between meaningful and nonsensical sentences. Still other analysts have been interested in creating formal, symbolic languages that are mathematical in nature. Their claim is that philosophical problems can be more effectively dealt with once they are formulated in a rigorous logical language.
By contrast, many philosophers associated with the movement have focused on the analysis of ordinary, or natural, language. Difficulties arise when concepts such as time and freedom, for example, are considered apart from the linguistic context in which they normally appear. Attention to language as it is ordinarily used is the key, it is argued, to resolving many philosophical puzzles.
Linguistic analysis as a method of philosophy is as old as the Greeks. Several of the dialogues of Plato, for example, are specifically concerned with clarifying terms and concepts. Nevertheless, this style of philosophizing has received dramatically renewed emphasis in the 20th century. Influenced by the earlier British empirical tradition of John Locke, George Berkeley, David Hume, and John Stuart Mill and by the writings of the German mathematician and philosopher Gottlob Frége, the 20th-century English philosopher”s G. E. Moore and Bertrand Russell became the founders of this contemporary analytic and linguistic trend. As students together at the University of Cambridge, Moore and Russell rejected Hegelian idealism, particularly as it was reflected in the work of the English metaphysician F. H. Bradley, who held that nothing is completely real except the Absolute. In their opposition to idealism and in their commitment to the view that careful attention to language is crucial in philosophical inquiry. They set the mood and style of philosophizing for much of the 20th century English-speaking world.
For Moore, philosophy was first and foremost analysis. The philosophical task involves clarifying puzzling propositions or concepts by indicating fewer puzzling propositions or concepts to which the originals are held to be logically equivalent. Once this task has been completed, the truth or falsity of problematic philosophical assertions can be determined more adequately. Moore was noted for his careful analyses of such puzzling philosophical claims as “time is unreal,” analyses that then aided in determining the truth of such assertions.
Russell, strongly influenced by the precision of mathematics, was concerned with developing an ideal logical language that would accurately reflect the nature of the world. Complex propositions, Russell maintained, can be resolved into their simplest components, which he called atomic propositions. These propositions refer to atomic facts, the ultimate constituents of the universe. The metaphysical views based on this logical analysis of language and the insistence that meaningful propositions must correspond to facts constitute what Russell called logical atomism. His interest in the structure of language also led him to distinguish between the grammatical form of a proposition and its logical form. The statements “John is good” and “John is tall” have the same grammatical form but different logical forms. Failure to recognize this would lead one to treat the property “goodness” as if it were a characteristic of John in the same way that the property “tallness” is a characteristic of John. Such failure results in philosophical confusion.
Russell”s work in mathematics attracted to Cambridge. The Austrian philosopher Ludwig Wittgenstein, who became a central figure in the analytic and linguistic movement. In his first major work, Tractatus Logico-philosophicus (1921; trans. 1922), in which he first presented his theory of language, Wittgenstein argued that “all philosophy is a “critique of language” and that “philosophy aims at the logical clarification of thoughts”. The results of Wittgenstein”s analysis resembled Russell”s logical atomism. The world, he argued, is ultimately composed of simple facts, which it is the purpose of language to picture. To be meaningful, statements about the world must be reducible to linguistic utterances that have a structure similar to the simple facts pictured. In this early Wittgensteinian analysis, only propositions that picture facts-the propositions of science-are considered factually meaningful. Metaphysical, theological, and ethical sentences were judged to be factually meaningless continues to exist between.
Influenced by Russell, Wittgenstein, Ernst Mach, and others, a group of philosophers and mathematicians in Vienna in the 1920s initiated the movement known as logical positivism. Led by Moritz Schlick and Rudolf Carnap, the Vienna Circle initiated one of the most important chapters in the history of analytic and linguistic philosophy. According to the positivist, the task of philosophy is the clarification of meaning, not the discovery of new facts (the job of the scientists) or the construction of comprehensive accounts of reality (the misguided pursuit of traditional metaphysics).
The positivist divided all meaningful assertions into two classes: analytic propositions and empirically verifiable ones. Analytic propositions, which include the propositions of logic and mathematics, are statements the truth or falsity of which depend together on the meanings of the terms constituting the statement. An example would be the proposition “two plus two equals four.” The second class of meaningful propositions includes all statements about the world that can be verified, at least in principle, by sense experience. Indeed, the meaning of such propositions is identified with the empirical method of their verification. This verifiability theory of meaning, the positivist concluded, would demonstrate that scientific statements are legitimate factual claims and that metaphysical, religious, and ethical sentences are factually empties. The ideas of logical positivism were made popular in England by the publication of A.J. Ayer”s Language, Truth and Logic in 1936.
The positivist” verifiability theory of meaning came under intense criticism by philosophers such as the Austrian-born British philosopher Karl Popper. Eventually this narrow theory of meaning yielded to a broader understanding of the nature of language. Again, an influential figure was Wittgenstein. Repudiating many of his earlier conclusions in the Tractatus, he initiated a new line of thought culminating in his posthumously published Philosophical Investigations (1953; trans. 1953). In this work, Wittgenstein argued that once attention is directed to the way language is actually used in ordinary discourse, the variety and flexibility of language become clear. Propositions do much more than simply picture facts.
This recognition led to Wittgenstein”s influential concept of language games. The scientist, the poet, and the theologian, for example, are involved in different language games. Moreover, the meaning of a proposition must be understood in its context, that is, in terms of the rules of the language game of which that proposition is a part. Philosophy, concluded Wittgenstein, is an attempt to resolve problems that arise as the result of linguistic confusion, and the key to the resolution of such problems is ordinary language analysis and the proper use of language.
Additional contributions within the analytic and linguistic movement include the work of the British philosopher's Gilbert Ryle, John Austin, and P. F. Strawson and the American philosopher W. V. Quine. According to Ryle, the task of philosophy is to restate “systematically misleading expressions” in forms that are logically more accurate. He was particularly concerned with statements the grammatical form of which suggests the existence of nonexistent objects. For example, Ryle is best known for his analysis of mentalistic language, language that misleadingly suggests that the mind is an entity in the same way as the body.
Austin maintained that one of the most fruitful starting points for philosophical inquiry is attention to the extremely fine distinctions drawn in ordinary language. His analysis of language eventually led to a general theory of speech acts, that is, to a description of the variety of activities that an individual may be performing when something is uttered.
Strawson is known for his analysis of the relationship between formal logic and ordinary language. The complexity of the latter, he argued, is inadequately represented by formal logic. A variety of analytic tools, therefore, are needed in addition to logic in analyzing ordinary language.
Quine discussed the relationship between language and ontology. He argued that language systems tend to commit their users to the existence of certain things. For Quine, the justification for speaking one way rather than another is a thoroughly pragmatic one.
The commitment to language analysis as a way of pursuing philosophy has continued as a significant contemporary dimension in philosophy. A division also those who prefer to work with the precision and rigor of symbolic logical systems and those who prefer to analyze ordinary language. Although few contemporary philosophers maintain that all philosophical problems are linguistic, the view continues to be widely held that attention to the logical structure of language and to how language is used in everyday discourse can often aid in resolving philosophical problems
Are terms of logical calculus are also called a formal language, and a logical system? A system in which explicit rules are provided to determining (1) which are the expressions of the system (2) which sequence of expressions count as well formed (well-forced formulae) (3) which sequence would count ss proofs. A system may include axioms for which leaves terminate a proof, however, it shows of the prepositional calculus and the predicated calculus.
It”s most immediate of issues surrounding certainty are especially connected with those concerning “scepticism.” Although Greek scepticism entered on the value of enquiry and questioning, scepticism is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics, or in any area whatsoever. Classical scepticism, springs from the observation that the best method in some area seems to fall short of giving us contact with the truth, e.g., there is a gulf between appearances and reality, it frequently cites the conflicting judgements that our methods deliver, with the result that questions of truth become undefinable. In classic thought the various examples of this conflict were systemized in the tropes of Aenesidemus. So that, the scepticism of Pyrrho and the new Academy was a system of argument and inasmuch as opposing dogmatism, and, particularly the philosophical system building of the Stoics.
As it has come down to us, particularly in the writings of Sextus Empiricus, its method was typically to cite reasons for finding our issue undesirable (sceptics devoted particular energy to undermining the Stoics conception of some truths as delivered by direct apprehension or some katalepsis). As a result the sceptic concludes eposhé, or the suspension of belief, and then go on to celebrate a way of life whose object was ataraxia, or the tranquillity resulting from suspension of belief.
Fixed by its will for and of itself, the mere mitigated scepticism which accepts every day or commonsense belief, is that, not the delivery of reason, but as due more to custom and habit. Nonetheless, it is self-satisfied at the proper time, however, the power of reason to give us much more. Mitigated scepticism is thus closer to the attitude fostered by the accentuations from Pyrrho through to Sextus Expiricus. Despite the fact that the phrase “Cartesian scepticism” is sometimes used. Descartes himself was not a sceptic, however, in the “method of doubt” uses a sceptical scenario in order to begin the process of finding a general distinction to mark its point of knowledge. Descartes trusts in categories of “clear and distinct” ideas, not far removed from the phantasiá kataleptikê of the Stoics.
For many sceptics had traditionally held that knowledge requires certainty, artistry. And, of course, they claim that certain knowledge is not possible. In part, nonetheless, of the principle that every effect it's a consequence of an antecedent cause or causes. For causality to be true it is not necessary for an effect to be predictable as the antecedent causes may be numerous, too complicated, or too interrelated for analysis. Nevertheless, in order to avoid scepticism, this participating sceptic has generally held that knowledge does not require certainty. Except for alleged cases of things that are evident for one just by being true. It has often been thought, that any thing known must satisfy certain criteria as well for being true. It is often taught that anything is known must satisfy certain standards. In so saying, that by “deduction” or “induction,” there will be criteria specifying when it is. As these alleged cases of self-evident truths, the general principle specifying the sort of consideration that will make such standards in the apparent or justly conclude in accepting it warranted to some degree.
Besides, there is another view-the absolute globular view that we do not have any knowledge whatsoever. In whatever manner, it is doubtful that any philosopher seriously entertains of an absolute scepticism. Even the Pyrrhonist sceptics, who held that we should refrain from accenting to any non-evident standards that no such hesitancy about asserting to “the evident,” the non-evident is any belief that requires evidences because it is warranted.
René Descartes (1596-1650), in his sceptical guise, never doubted the content of his own ideas. It”s challenging logic, inasmuch as of whether they “corresponded” to anything beyond ideas.
All the same, Pyrrhonism and Cartesian form of a virtual globular scepticism, in having been held and defended, that of assuming that knowledge is some form of true, sufficiently warranted belief, it is the warranted condition that provides the truth or belief conditions, in that of providing the grist for the sceptic”s mill about. The Pyrrhonist will suggest that no non-evident, empirically deferring the sufficiency of giving in but warranted. Whereas, a Cartesian sceptic will agree that no empirical standard about anything other than one”s own mind and its contents is sufficiently warranted, because there are always legitimate grounds for doubting it. Whereby, the essential difference between the two views concerns the stringency of the requirements for a belief being sufficiently warranted to take account of as knowledge.
A Cartesian requires certainty. A Pyrrhonist merely requires that the standards in case are more warranted then its negation.
Cartesian scepticism was by an unduly influence with which Descartes agues for scepticism, than his reply holds, in that we do not have any knowledge of any empirical standards, in that of anything beyond the contents of our own minds. The reason is roughly in the position that there is a legitimate doubt about all such standards, only because there is no way to justifiably deny that our senses are being stimulated by some sense, for which it is radically different from the objects which we normally think, in whatever manner they affect our senses. Therefrom, if the Pyrrhonist are the agnostic, the Cartesian sceptic is the atheist.
Because the Pyrrhonist require much less of a belief in order for it to be confirmed as knowledge than do the Cartesian, the argument for Pyrrhonism are much more difficult to construct. A Pyrrhonist must show that there is no better set of reasons for believing to any standards, of which are in case that any knowledge learnt of the mind is understood by some of its forms, that has to require certainty.
The underlying latencies that are given among the many derivative contributions as awaiting their presence to the future that of specifying to the theory of knowledge, is, but, nonetheless, the possibility to identify a set of shared doctrines, however, identity to discern two broad styles of instances to discern, in like the manner, these two styles of pragmatism, clarify the innovation that a Cartesian approval is fundamentally flawed, nonetheless, of responding very differently but not fordone.
Repudiating the requirements of absolute certainty or knowledge, insisting on the connection of knowledge with activity, as, too, of pragmatism of a reformist distributing knowledge upon the legitimacy of traditional questions about the truth-unconductiveness of our cognitive practices, and sustain a conception of truth objectives, enough to give those questions that undergo of a gathering in their own purposive latencies, yet we are given to the spoken word for which a dialectic awareness sparks the flame from the ambers of fire.
Pragmatism of a determinant revolution, by contrast, relinquishing the objectivity of youth, acknowledges no legitimate epistemological questions over and above those that are naturally kindred of our current cognitive conviction.
It seems clear that certainty is a property that can be assembled to either a person or a belief. We can say that a person, “S” is certain, or we can say that its descendable alinement are aligned as of “p”, is certain. The two uses can be connected by saying that “S” has the right to be certain just in case the value of “p” is sufficiently verified.
In defining certainty, it is crucial to note that the term has both an absolute and relative sense. More or less, we take a proposition to be certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectively a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or ever possible, either for any proposition at all, or for any proposition from some suspect family (ethics, theory, memory, empirical judgement etc.) a major sceptical weapon is the possibility of upsetting events that Can cast doubt back onto what were hitherto taken to be certainties. Others include reminders of the divergence of human opinion, and the fallible source of our confidence. Fundamentalist approaches to knowledge look for a basis of certainty, upon which the structure of our system is built. Others reject the metaphor, looking for mutual support and coherence, without foundation.
However, in moral theory, the view that there are inviolable moral standards or absolute variable human desires or policies or prescriptions.
In spite of the notorious difficulty of reading Kantian ethics, a hypothetical imperative embeds a command which is in place only given some antecedent desire or project: “If you want to look wise, stay quiet”. The injunction to stay quiet only applies to those with the antecedent desire or inclination. If one has no desire to look wise the injunction cannot be so avoided: It is a requirement that binds anybody, regardless of their inclination. It could be represented as, for example, “tell the truth (regardless of whether you want to or not)”. The distinction is not always signalled by presence or absence of the conditional or hypothetical form: “If you crave drink, don't become a bartender” may be regarded as an absolute injunction applying to anyone, although only activated in case of those with the stated desire.
In Grundlegung zur Metaphsik der Sitten (1785), Kant discussed five forms of the categorical imperative: (1) the formula of universal law: “act only on that maxim through which you can at the same times will that it should become universal law: (2) the formula of the law of nature: “act as if the maxim of your action were to become through your will a universal law of nature”: (3) the formula of the end-in-itself: “act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end”: (4) the formula of autonomy, or considering “the will of every rational being as a will which makes universal law”: (5) the formula of the Kingdom of Ends, which provides a model for the systematic union of different rational beings under common laws.
Even so, a proposition that is not a conditional “p”. Moreover, the affirmative and negative, modern opinion is wary of this distinction, since what appears categorical may vary notation. Apparently, categorical propositions may also turn out to be disguised conditionals: “X” is intelligent (categorical?) = if “X” is given a range of tasks she performs them better than many people (conditional?) The problem. Nonetheless, is not merely one of classification, since deep metaphysical questions arise when facts that seem to be categorical and therefore solid, come to seem by contrast conditional, or purely hypothetical or potential.
A limited area of knowledge or endeavour to which pursuits, activities and interests are a central representation held to a concept of physical theory. In this way, a field is defined by the distribution of a physical quantity, such as temperature, mass density, or potential energy y, at different points in space. In the particularly important example of force fields, such as gravitational, electrical, and magnetic fields, the field value at a point is the force which a test particle would experience if it were located at that point. The philosophical problem is whether a force field is to be thought of as purely potential, so the presence of a field merely describes the propensity of masses to move relative to each other, or whether it should be thought of in terms of the physically real modifications of a medium, whose properties result in such powers that is, are force fields purely potential, fully characterized by dispositional statements or conditionals, or are they categorical or actual? The former option seems to require within ungrounded dispositions, or regions of space that differs only in what happens if an object is placed there. The law-like shape of these dispositions, apparent for example in the curved lines of force of the magnetic field, may then seem quite inexplicable. To atomists, such as Newton it would represent a return to Aristotelian entelechies, or quasi-psychological affinities between things, which are responsible for their motions. The latter option requires understanding of how forces of attraction and repulsion can be “grounded” in the properties of the medium.
The basic idea of a field is arguably present in Leibniz, who was certainly hostile to Newtonian atomism. Although his equal hostility to “action at a distance” muddies the water. It is usually credited to the Jesuit mathematician and scientist Joseph Boscovich (1711-87) and Immanuel Kant (1724-1804), both of whom influenced the scientist Faraday, with whose work the physical notion became established. In his paper “On the Physical Character of the Lines of Magnetic Force” (1852). Faraday was to suggest several criteria for assessing the physical reality of lines of force, such as whether they are affected by an intervening material medium, whether the motion depends on the nature of what is placed at the receiving end. As far as electromagnetic fields go, Faraday himself inclined to the view that the mathematical similarity between heat flow, currents, and electro-magnetic lines of force was evidence for the physical reality of the intervening medium.
Once, again, our mentioning recognition for which its case value, whereby its view is especially associated the American psychologist and philosopher William James (1842-1910), that the truth of a statement can be defined in terms of a “utility” of accepting it. Communicated, so much as a dispiriting position for which its place of valuation may be viewed as an objection. Since there are things that are false, as it may be useful to accept, and conversely there are things that are true and that it may be damaging to accept. Nevertheless, there are deep connections between the idea that a representation system is accorded, and the likely success of the projects in progressive formality, by its possession. The evolution of a system of representation either perceptual or linguistic, seems bounded to connect successes with everything adapting or with utility in the modest sense. The Wittgenstein doctrine stipulates the meaning of use that upon the nature of belief and its relations with human attitude, emotion and the idea that belief in the truth on one hand, the action of the other. One way of binding with cement, wherefore the connection is found in the idea that natural selection becomes much as much in adapting us to the cognitive creatures, because beliefs have effects, they work. Pragmatism can be found in Kant”s doctrine, and continued to play an influencing role in the theory of meaning and truth.
James, (1842-1910), although with characteristic generosity exaggerated in his debt to Charles S. Peirce (1839-1914), he charted that the method of doubt encouraged people to pretend to doubt what they did not doubt in their hearts, and criticize its individualist”s insistence, that the ultimate test of certainty is to be found in the individuals personalized consciousness.
From his earliest writings, James understood cognitive processes in teleological terms. Though, he held us in the satisfactory interests. His will to Believe doctrine, the view that we are sometimes justified in believing beyond the evidential relics upon the notion that a belief's benefits are relevant to its justification. His pragmatic method of analysing philosophical problems, for which requires that we find the meaning of terms by examining their application to objects in experimental situations, similarly reflects the teleological approach in its attention to consequences.
Such an approach, however, sets ”James” theory of meaning apart from verification, dismissive of metaphysics. Unlike the verification alist, who takes cognitive meaning to be a matter only of consequences in sensory experience. James” took pragmatic meaning to include emotional and matter responses. Moreover, his ,metaphysical standard of value, not a way of dismissing them as meaningless. It should also be noted that in a greater extent, circumspective moment's James did not hold that even his broad set of consequences were exhaustive of a terms meaning. “Theism”, for example, he took to have antecedently, definitional meaning, in addition to its varying degree of importance and chance upon an important pragmatic meaning.
James” theory of truth reflects upon his teleological conception of cognition, by considering a true belief to be one which is compatible with our existing system of beliefs, and leads us to satisfactory interaction with the world.
However, Peirce”s famous pragmatist principle is a rule of logic employed in clarifying our concepts and ideas. Consider the claim the liquid in a flask is an acid, if, we believe this, we except that it would turn red: We accept an action of ours to have certain experimental results. The pragmatic principle holds that listing the conditional expectations of this kind, in that we associate such immediacy with applications of a conceptual representation that provides a complete and orderly sets clarification of the concept. This is relevant ti the logic of abduction: Clarificationists using the pragmatic principle provides all the information about the content of a hypothesis that is relevantly to decide whether it is worth testing.
To a greater extent, and what is most important, is the famed apprehension of the pragmatic principle, in so that, Pierces”s account of reality: When we take something to be rea that by this single case, we think it is “fated to be agreed upon by all who investigate” the matter to which it stand, in other words, if I believe that it is really the case that “P”, then I except that if anyone were to inquire depthfully into the finding its measure into whether “p”, they would arrive at the belief that “p”. It is not part of the theory that the experimental consequences of our actions should be specified by a warranted empiricist vocabulary-Peirce insisted that perceptual theories are abounding in latency. Even so, nor is it his view that the collected conditionals do or not clarify a concept as all analytic. In addition, in later writings, he argues that the pragmatic principle could only be made plausible to someone who accepted its metaphysical realism: It requires that “would-bees” are objective and, of course, real.
If realism itself can be given a fairly quick clarification, it is more difficult to chart the various forms of supposition, for they seem legendary. Other opponents deny that the entitles posited by the relevant discourse that exist or at least exists: The standard example is “idealism”, which reality is somehow mind-curative or mind-co-ordinated-that real object comprising the “external world” are not independently of eloping minds, but only exist as in some way correlative to the mental operations. The doctrine assembled of “idealism” enters on the conceptual note that reality as we understand this as meaningful and reflects the working of mindful purposes. And it construes this as meaning that the inquiring mind itself makes of a formative constellations and not of any mere understanding of the nature of the “real” bit even the resulting charger we attribute to it.
Wherefore, the term ids most straightforwardly used when qualifying another linguistic form of Grammatik: a real “x” may be contrasted with a fake, a failed “x”, a near “x”, and so on. To trat something as real, without qualification, is to suppose it to be part of the actualized world. To reify something is to suppose that we have committed by some indoctrinated treatise, as that of a theory. The central error in thinking of reality and the totality of existence is to think of the “unreal” as a separate domain of things, perhaps, unfairly to that of the benefits of existence.
Such that non-existence of all things, as the product of logical confusion of treating the term “nothing” as itself a referring expression instead of a “quantifier”. (Stating informally as a quantifier is an expression that reports of a quantity of times that a predicate is satisfied in some class of things, i.e., in a domain.) This confusion leads the unsuspecting to think that a sentence such as “Nothing is all around us” talks of a special kind of thing that is all around us, when in fact it merely denies that the predicate “is all around us” has appreciations. The feelings that lad some philosophers and theologians, notably Heidegger, to talk of the experience of. Nothing, is not properly the experience of anything, but rather the failure of a hope or expectations that there would be something of some kind at some point. This may arise in quite everyday cases, as when one finds that the article of functions one expected to see as usual, in the corner has disappeared. The difference between “existentialist” and “analytic philosophy”, on the point of what, whereas the former is afraid of nothing, and the latter thinks that there is nothing to be afraid of.
A rather different set of concerns arise when actions are specified in terms of doing nothing, saying nothing may be an admission of guilt, and doing nothing in some circumstances may be tantamount to murder. Still, other substitutional problems arise over conceptualizing empty space and time.
Whereas, the standard opposition between those who affirm and those who deny, the real existence of some kind of thing or some kind of fact or state of affairs. Almost any area of discourse may be the focus of this dispute: The external world, the past and future, other minds, mathematical objects, possibilities, universals, moral or aesthetic properties are examples. There be to one influential suggestion, as associated with the British philosopher of logic and language, and the most determinative of philosophers centred round Anthony Dummett (1925), to which is borrowed from the “intuitionistic” critique of classical mathematics, and suggested that the unrestricted use of the “principle of bivalence” is the trademark of “realism”. However, this ha to overcome counter-examples both ways: Although Aquinas wads a moral “realist”, he held that moral really was not sufficiently structured to make true or false every moral claim. Unlike Kant who believed that he could use the law of bivalence happily in mathematics, precisely because it wad only our own construction. Realism can itself be subdivided: Kant, for example, combines empirical realism (within the phenomenal world the realist says the right things-surrounding objects really exist and independent of us and our mental stares) with transcendental idealism (the phenomenal world as a whole reflects the structures imposed on it by the activity of our minds as they render it intelligible to us). In modern philosophy the orthodox oppositions to realism has been from philosopher such as Goodman, who, impressed by the extent to which we perceive the world through conceptual and linguistic lenses of our own making.
Assigned to the modern treatment of existence in the theory of “quantification” is sometimes put by saying that existence is not a predicate. The idea is that the existential quantifies themselves as an operator on a predicate, indicating that the property it expresses has instances. Existence is therefore treated as a second-order property, or a property of properties. It is fitting to say, that in this it is like number, for when we say that these things of a kind, we do not describe the thing (ad we would if we said there are red things of the kind), but instead attribute a property to the kind itself. The parallelled numbers are exploited by the German mathematician and philosopher of mathematics Gottlob Frége in the dictum that affirmation of existence is merely denied of the number nought. A problem, nevertheless, proves accountable for it”s crated by sentences like “This exists”, where some particular thing is undirected, such that a sentence seems to express a contingent truth (for this insight has not existed), yet no other predicate is involved. “This exists” is, and unlike “Tamed tigers exist”, where a property is said to have an instance, for the word “this” and does not locate a property, but only an individual.
Possible worlds seem able to differ from each other purely in the presence or absence of individuals, and not merely in th distribution of exemplification of properties.
The philosophical ponderance over which to set upon the unreal, as belonging to the domain of Being. Nonetheless, there is little for us that can be said with the philosopher”s study. So it is not apparent that there can be such a subject for being by itself. Nevertheless, the concept had a central place in philosophy from Parmenides to Heidegger. The essential question of “why is there something and not of nothing?" Prompting over logical reflection on what it is for a universal to have an instance, nd as long history of attempts to explain contingent existence, by which id to reference and a necessary ground.
In the transition, ever since Plato, this ground becomes a self-sufficient, perfect, unchanging, and external something, identified with the Good or God, but whose relation with the everyday world remains obscure. The celebrated argument for the existence of God first propounded by Anselm in his Proslogin. The argument by defining God as “something than which nothing greater can be conceived”. God then exists in the understanding since we understand this concept. However, if, He only existed in the understanding something greater could be conceived, for a being that exists in reality is greater than one that exists in the understanding. Bu then, we can conceive of something greater than that than which nothing greater can be conceived, which is contradictory. Therefore, God cannot exist on the understanding, but exists in reality.
An influential argument (or family of arguments) for the existence of God, finding its premisses are that all natural things are dependent for their existence on something else. The totality of dependent brings must then itself depend upon a non-dependent, or necessarily existent bring of which is God. Like the argument to design, the cosmological argument was attacked by the Scottish philosopher and historian David Hume (1711-76) and Immanuel Kant.
Its main problem, nonetheless, is that it requires us to make sense of the notion of necessary existence. For if the answer to the question of why anything exists is that some other tings of a similar kind exists, the question merely arises gain. So the “God” that ends the question must exist necessarily: It must not be an entity of which the same kinds of questions can be raised. The other problem with the argument is attributing concern and care to the deity, not for connecting the necessarily existent being it derives with human values and aspirations.
The ontological argument has been treated by modern theologians such as Barth, following Hegel, not so much as a proof with which to confront the unconverted, but as an explanation of the deep meaning of religious belief. Collingwood, regards the argument s proving not that because our idea of God is that of id quo maius cogitare viequit, therefore God exists, but proving that because this is our idea of God, we stand committed to belief in its existence. Its existence is a metaphysical point or absolute presupposition of certain forms of thought.
In the 20th century, modal versions of the ontological argument have been propounded by the American philosophers Charles Hertshorne, Norman Malcolm, and Alvin Plantinge. One version is to define something as unsurpassably great, if it exists and is perfect in every “possible world”. Then, to allow that it is at least possible that an unsurpassable great being existed. This means that there is a possible world in which such a being exists. However, if it exists in one world, it exists in all (for the fact that such a being exists in a world that entails, in at least, it exists and is perfect in every world), so, it exists necessarily. The correct response to this argument is to disallow the apparently reasonable concession that it is possible that such a being exists. This concession is much more dangerous than it looks, since in the modal logic, involved from possibly necessarily “p”, we can device necessarily “p”. A symmetrical proof starting from the assumption that it is possibly that such a being not exist would derive that it is impossible that it exists.
The doctrine that it makes an ethical difference of whether an agent actively intervenes to bring about a result, or omits to act in circumstances in which it is foreseen, that as a result of the omission the same result occurs. Thus, suppose that I wish you dead. If I act to bring about your death, I am a murderer, however, if I happily discover you in danger of death, and fail to act to save you, I am not acting, and therefore, according to the doctrine of acts and omissions not a murderer. Critics implore that omissions can be as deliberate and immoral as I am responsible for your food and fact to feed you. Only omission is surely a killing, “Doing nothing” can be a way of doing something, or in other worlds, absence of bodily movement can also constitute acting negligently, or deliberately, and defending on the context ,may be a way of deceiving, betraying, or killing. Nonetheless, criminal law offers to find its conveniences, from which to distinguish discontinuous intervention, for which is permissible, from bringing about result, which may not be, if, for instance, the result is death of a patient. The question is whether the difference, if there is one, is, between acting and omitting to act be discernibly or defined in a way that bars a general moral might.
The double effect of a principle attempting to define when an action that had both good and bad results is morally permissible. I one formation such an action is permissible if (1) The action is not wrong in itself, (2) the bad consequences is not that which is intended (3) the good is not itself a result of the bad consequences, and (4) the two consequential effects are commensurate. Thus, for instance, I might justifiably bomb an enemy factory, foreseeing but intending that the death of nearby civilians, whereas bombing the death of nearby civilians intentionally would be disallowed. The principle has its roots in Thomist moral philosophy, accordingly. St. Thomas Aquinas (1225-74), held that it is meaningless to ask whether a human being is two tings (soul and body) or, only just as it is meaningless to ask whether the wax and the shape given to it by the stamp are one: On this analogy the sound is ye form of the body. Life after death is possible only because a form itself doe not perish (pricking is a loss of form).
accepted that trying to make the connection between thought and experience through basic sentence s depends on an untenable myth of the given
The special way that we each have of knowing our own thoughts, intentions, and sensationalist have brought in the many philosophical behaviorist and functionalist tendencies, that have found it important to deny that there is such a special way , arguing the way that I know of my own mind inasmuch as the way that I know of yours, e.g., by seeing what I say when asked. Others, however, point out that the behaviour of reporting the result of introspection in a particular and legitimate kind of behavioural access that deserves notice in any account of historically human psychology. The historical philosophy of reflection upon the astute of history, or of historical, thinking, finds the term was used in the 18th century, e.g., by Volante was to mean critical historical thinking as opposed to the mere collection and repetition of stories about the past. In Hegelian, particularly by conflicting elements within his own system, however, it came to man universal or world history. The Enlightenment confidence was being replaced by science, reason, and understanding that gave history a progressive moral thread, and under the influence of the German philosopher, whom is in spreading Romanticism, came Gottfried Herder (1744-1803),and, Immanuel Kant, this idea took it further to hold, so that philosophy of history cannot be the detecting of a grand system, the unfolding of the evolution of human nature as witnessed in successive sages (the progress of rationality or of Spirit). This essential speculative philosophy of history is given a extra Kantian twist in the German idealist Johann Fichte, in whom the extra association of temporal succession with logical implication introduces the idea that concepts themselves are the dynamic engine of historical change. The idea is readily intelligible in that their world of nature and of thought become identified. The work of Herder, Kant, Flichte and Schelling is synthesized by Hegel: History has a plot, as too, this to the moral development of man, equates with freedom within the state, this in turn is the development of thought, or a logical development in which various necessary moment in the life of the concept are successively achieved and improved upon. Hegel”s method is at it’s most successful, when the object is the history of ideas, and the evolution of thinking may march in steps with logical oppositions and their resolution encounters red by various systems of thought.
Within the revolutionary communism, Karl Marx (1818-83) and the German social philosopher Friedrich Engels (1820-95), there emerges a rather different kind of story, based upon Hefl's progressive structure not laying the achievement of the goal of history to a future in which the political condition for freedom comes to exist, so that economic and political fears than “reason” is in the engine room. Although, it is such that speculations upon the history may that it be continued to be written, notably: late examples, by the late 19th century large-scale speculation of tis kind with the nature of historical understanding, and in particular with a comparison between the ,methos of natural science and with the historians. For writers such as the German neo-Kantian Wilhelm Windelband and the German philosopher and literary critic and historian Wilhelm Dilthey, it is important to show that the human sciences such as history is objective and legitimate, nonetheless they are in some way deferent from the enquiry of the scientist. Since the subjective-matter is the past thought and actions of human brings, what is needed and actions of human beings, past thought and actions of human beings, what is needed is an ability to re-live that past thought, knowing the deliberations of past agents, as if they were the historian's own. The most influential British writer on this theme was the philosopher and historian George Collingwood (1889-1943) whose, The Idea of History (1946), contains an extensive defence of the verstehe approach, but it is nonetheless, the explanation from their actions, however, by re-living the situation as our understanding that understanding others is not gained by the tactic use of a “theory”, enabling us to infer what thoughts or intentionality experienced, again, the matter to which the subjective-matters of past thoughts and actions , as I have a human ability of knowing the deliberations of past agents as if they were the historian”s own. The immediate question of the form of historical explanation, and the fact that general laws have other than no place or any apprentices in the order of a minor place in the human sciences, it is also prominent in thoughts about distinctiveness as to regain their actions, but by re-living the situation in or thereby understanding of what they experience and thought.
By Comparison, Bolzano argues, though, that there is something else, an infinity that doe not have this ‘whatever you need it to be’ elasticity. In fact a truly infinite quantity (for example, the length of a straight line unbounded in either direction, meaning: The magnitude of the spatial entity containing all the points determined solely by their abstractly conceivable relation to two fixed points) does not by any means need to be variable, and in adduced example it is in fact not variable. Conversely, it is quite possible for a quantity merely capable of being taken greater than we have already taken it, and of becoming larger than any pre-assigned (finite) quantity, nevertheless to mean at all times merely finite, which holds in particular of every numerical quantity 1, 2, 3, 4, 5.
In other words, for Bolzano there could be a true infinity that was not a variable ‘something’ that was only bigger than anything you might specify. Such a true infinity was the result of joining two pints together and extending that line in both directions without stopping. And what is more, he could separate off the demands of calculus, using a finite quality without ever bothering with the slippery potential infinity. Here was both a deeper understanding of the nature of infinity and the basis on which are built in his ‘safe’ infinity free calculus.
This use of the inexhaustible follows on directly from most Bolzano’s criticism of the way that ∞ we used as a variable something that would be bigger than anything you could specify, but never quite reached the true, absolute infinity. In Paradoxes of the Infinity Bolzano points out that is possible for a quantity merely capable of becoming larger than any one pre-assigned (finite) quantity, nevertheless to remain at all times merely finite.
Bolzano intended tis as a criticism of the way infinity was treated, but Professor Jacquette sees it instead of a way of masking use of practical applications like calculus without the need for weasel words about infinity.
By replacing ∞ with ¤ we do away with one of the most common requirements for infinity, but is there anything left that map out to the real world? Can we confine infinity to that pure mathematical other world, where anything, however unreal, can be constructed, and forget about it elsewhere? Surprisingly, this seems to have been the view, at least at one point in time, even of the German mathematician and founder of set-theory Georg Cantor (1845-1918), himself, whose comments in 1883, that only the finite numbers are real.
Keeping within the lines of reason, both the Cambridge mathematician and philosopher Frank Plumpton Ramsey (1903-30) and the Italian mathematician G. Peano (1858-1932) have been to distinguish logical paradoxes and that depend upon the notion of reference or truth (semantic notions), such are the postulates justifying mathematical induction. It ensures that a numerical series is closed, in the sense that nothing but zero and its successors can be numbers. In that any series satisfying a set of axioms can be conceived as the sequence of natural numbers. Candidates from set theory include the Zermelo numbers, where the empty set is zero, and the successor of each number is its unit set, and the von Neuman numbers, where each number is the set of all smaller numbers. A similar and equally fundamental complementarity exists in the relation between zero and infinity. Although the fullness of infinity is logically antithetical to the emptiness of zero, infinity can be obtained from zero with a simple mathematical operation. The division of many numbers by zero is infinity, while the multiplication of any number by zero is zero.
With the set theory developed by the German mathematician and logician Georg Cantor. From 1878 to 1807, Cantor created a theory of abstract sets of entities that eventually became a mathematical discipline. A set, as he defined it, is a collection of definite and distinguished objects in thought or perception conceived as a whole.
Cantor attempted to prove that the process of counting and the definition of integers could be placed on a solid mathematical foundation. His method was to repeatedly place the elements in one set into ‘one-to-one’ correspondence with those in another. In the case of integers, Cantor showed that each integer (1, 2, 3, . . . n) could be paired with an even integer (2, 4, 6, . . . n), and, therefore, that the set of all integers was equal to the set of all even numbers.
Amazingly, Cantor discovered that some infinite sets were large than others and that infinite sets formed a hierarchy of greater infinities. After this failed attempt to save the classical view of logical foundations and internal consistency of mathematical systems, it soon became obvious that a major crack had appeared in the seemingly sold foundations of number and mathematics. Meanwhile, an impressive number of mathematicians began to see that everything from functional analysis to the theory of real numbers depended on the problematic character of number itself.
While, in the theory of probability Ramsey was the first to show how a personalised theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a ‘redundancy theory of truth’, which hr combined with radical views of the function of man y kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentence affirmed in a scientific theory that use some term, e.g., ‘quark’. Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the ‘topic-neutral’ structure of the theory, but removes any implications that we know what the term so treated denote. I t leaves open the possibility of identifying the theoretical item with whatever it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
It seems, that the most taken of paradoxes in the foundations of ‘set theory’ as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no to easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed that paradoses like those of Russell nd the ‘barber’ were due to such as the impredicative definitions, and therefore proposed banning them. But, it tuns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen as being an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? s there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all th special science? For much of the 20th century there questions were pursued in a highly abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truth or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophical understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which stricture sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by ‘natural light’ or reason, and (in religion versions of the theory) that express God’s will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God’ s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supped of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of ‘moral’ considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test they are the edicts of a divine lawmaker, or that they are truths of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situation ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kant’s own applications of the notion are not always convincing, as for one cause of confusion in relating Kant’s ethics to theories such additional expressivism is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something ‘unconditional’ or ‘necessary’ such as the voice of reason.
For which ever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in onself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such as being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of ‘deontological’ approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive percreptive, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that thy can be external to the believer’s cognitive perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase ‘cognitively accessible’ suggests the weak interpretion, the main intuitive motivation for internalism, viz the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a coherent view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them).
The most prominent recent externalist views have been versions of reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true , but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in ‘normal’ possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilist can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliablist condition is satisfied.
One sort of response to this latter sorts of objection is to ‘bite the bullet’ and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
A view in this same general vein, one that might be described as a hybrid of internalism and externalism holds that epistemic justification requires that there is a justicatory factor that is cognitively accessible to the believer in question (though it need not be actually grasped), thus ruling out, e.g., a pure reliabilism. At the same time, however, though it must be objectively true that beliefs for which such a factor is available are likely to be true, in addition, the fact need not be in any way grasped or cognitively accessible to the believer. In effect, of the premises needed to argue that a particular belief is likely to be true, one must be accessible in a way that would satisfy at least weak internalism, the internalist will respond that this hybrid view is of no help at all in meeting the objection and has no belief nor is it held in the rational, responsible way that justification intuitively seems to require, for the believer in question, lacking one crucial premise, still has no reason at all for thinking that his belief is likely to be true.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adults posses knowledge, though not the weaker conviction (if such a conviction does exists) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, th an knowledge?`
A rather different use of the terms ‘internalism’ and ‘externalism’ has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual’s mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as ‘direct reference’ theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment-e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc.-not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought ‘from the inside’, simply by reflection. If content is depend on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors-which will not in general be available to the person whose belief or thought is in question.
The more we are understood, and concede to holism as an inescapable condition of our physical existence, according to theory, each individual of the system in a certain sense, at any-one time, exists simultaneously in every part of the space occupied by the system. Its physical reality must be described as to continuous functions in space. The material point, therefore, can hardly be anticipated any more than the basic concept of theory.
A human being is part of the whole, and he experiences himself, his thoughts and feelings as something separate from the rest-a kind of optical illusion of his consciousness. This delusion is kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody could achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security.
The more the universe seems comprehensible, the more it seems pointless, just as life is merely a disease of matter, and, so, I think, any attempts to preserve this view not only require metaphysical leaps that result in unacceptable levels of ambiguity. They also fail to meet the requirement that testability is necessary to confirm the validity of all theoretical undertakings.
From its start, the languages of biblical literature were equally valid sources of communion with the eternal and immutable truths exiting in the mind of God, yet the extant documents alone were consisted with more than a million words in his own hand, and some of his speculations seem quite bizarre by contemporary standards, least of mention, they deem of a sacred union with which on the appearance of an unexamined article of faith, expanding our worship upon some altar of an unknown god.
Our inherent consciousness, as the corpses of times generations were to evolve, having distributively confirmed a striking unity, as unified consciousness can take more than one form, it is, nonetheless that when we are consciously aware that we are capably communicable of a conscious content, in a dialectic awareness of several conscious states that seem alternatively assembled.
As no assumption can be taken for granted, and no thoughtful conclusion should be lightly dismissed as fallacious in studying the phenomenon of consciousness, nonetheless, which of exercising intellectual humanity and caution we must try to move ahead to reach some positive conclusion upon its topic.
Our consciousness shows us of a striking unity, as unified consciousness can take more than one form, it is, nonetheless that when we are consciously aware that we are capably communicable of a conscious content, in a dialectic awareness of several conscious states that seem alternatively assembled. Mental states have related us interconnectively as given among us. Because, I am aware not of 'A' and the separability of 'B' and independence of 'C', but am dialectically aware of 'A-and-B-and-C', simultaneously, or better, as all parts of the content of a single conscious state. Since from the time of Kant, persuading with reason that sets itself the good use the faculty arising to engage the attaining knowledge to be considered the name designated as this phenomenon imposes and responds to definite qualities as the ‘unity of consciousness’.
Historically, the notion of the unity of consciousness has played a very large role in thought about the mind. Of this point in fact, it figured centrally in most influential arguments about the mind from the time of Descartes to the 20th century. In the early part of the 20th century, the notion largely disappeared for a time. Analytic philosophers began to pay attention to it again only in the 1960s. We unstretchingly distribute some arranging affirmation that this history subsisted up til the nineteen-hundreds. At that point, we should delineate the unity of consciousness more carefully and examine some evidence from neuropsychology because both are necessary to understand the recent work on the issue.
Descartes would assert that if the partialities existent to the parts have not constructed the constituents parts that decide of its partiality, it cannot contain matter, presumably because, as he saw it, anything material has parts. He then goes on to say that this would be enough to prove dualism by itself, had he not already proved it elsewhere. Recognizing where it is that I cannot distinguish any parts, as accumulatively collected through Unified consciousness is that, it may, have converged of itself.
Directly of another, moderately compound argument based on unified consciousness. The conclusion will be that any system of components could never achieve unified consciousness acting in concert. William James' well-known version of the argument starts as follows: Take a sentence of a dozen words, take twelve men, and to each word. Then stand the men in a row or jam them in a bunch, and let each think of his word as intently as he will, no where will there be a consciousness of the whole sentence.
James generalizes this observation to all conscious states. To get dualism out of this, we need to add the premise, that if whatever makes up the pursuing situations that mind is considered the supreme reality and have the ultimate means. Tenably to assert the creation from a speculative assumption that bestows to its beginning that makes inherent descendabilities the value for which of existence may so be embraced of the mind of matter. A variable takes the corresponding definitive criteria of possibilities in value accorded with reality, and would have distributed the relational states that consciousness expresses over some group of components in some relevant way. Still, this thought experiment is meant to show that they cannot so distribute conscious states. Therefore, the conscious mind is not made out of matter, recounting the argument that James is attending the use of the Unity Argument. Clearly, the idea that our consciousness of, here, the parts of a sentence are unified is at the centre of the Unity Argument. Like the first, this argument goes all the way back to Descartes. Versions of it can be found in thinkers otherwise as different from one another as Leibniz, Reid, and James. The Unity Argument continued to be persuasively influential into the 20th century. That the argument was considered a powerful reason for concluding that the mind is not the body is illustrated in a backhanded way by Kant's treatment of it (as he found it in Descartes and Leibniz, not James, of course).
Kant did not think that we could explain anything about the nature of the mind, including whether or not it is made out of matter. To make the case for this view, he had to show that all existing arguments that the mind is not material do not work. He sets out to do just of something that is or should be perceived as real nor present to the senses the image so formed can confront and deal with reality by using the derivative powers of mind, as in the Critique of Pure Reason on the Paralogisms of Pure Reason (1781) (paralogisms are faulty inferences about the nature of the mind). The Unity Argument is the target of a major part of that chapter; if one is going to show that we cannot know what the mind is like, we must dispose of the Unity Argument, which purports to show that the mind is not made out of matter. Kant's argument that the Unity Argument does not support dualism is simple. He urges that the idea of unified consciousness being achieved by something that has no parts or components be no less mysterious than its being achieved by a system of components acting together. Remarkably enough, although no philosopher has ever met this challenge of Kant's and no account exists of what an immaterial mind not made out of parts might be like, philosophers continued to rely on the Unity Argument until well into the 20th century. It may be a bit difficult for us to capture this now but the idea that unified consciousness could not be realized by any system of components, and for an even stronger reason any system of material components, had a strong intuitive appeal for a long time.
Again, the historical notion in the unity of consciousness has had an interesting history in philosophy and psychology. Taking Descartes to be the first major philosopher of the modern period, the unity of consciousness was central to the study of the mind for the whole of the modern period until the 20th century. The notion figured centrally in the work of Descartes, Leibniz, Hume, Reid, Kant, Brennan, James, even in most of the major precursors of contemporary philosophy of mind and cognitive psychology. It played a particularly important role in Kant's work.
A couple of examples will illustrate the role that the notion of the unity of consciousness played in this long literature. Consider a classical argument for dualism (the view that the mind is not the body, in fact, not made out of matter at all). It starts like this: When I consider the mind, which is say, myself because I am only a thinking thing, I cannot distinguish in myself any parts, but apprehend myself to be clearly one and entire.
Descartes, asserts that if the mind is not made up of parts, it cannot be made of matter, presumably because, as he saw it, anything material has parts. He then goes on to say that this would be enough to prove dualism by itself, had he not already proved it elsewhere. Recognizing where it is that I cannot distinguish any parts, because on account that unified consciousness has initiated upon me.
James generalizes this observation to all conscious states. To get dualism out of this, we need to add a premise: That if the mind were made out of matter, conscious states would have to be distributed over some group of components in some relevant way. Nonetheless, this thought experiment is meant to show that conscious states cannot be so distributed. Therefore, the conscious mind is not made out of matter. Calling the argument that James is using here the Unity Argument. Clearly, the idea that our consciousness of or for itself, the parts of a sentence that are unified are at the centre of the Unity Argument. Like the first, this argument goes all the way back to Descartes. Versions of it can be found in thinkers otherwise as different from one another as Leibniz, Reid, and James. The Unity Argument continued to be influential into the 20th century. That the argument was considered a powerful reason for concluding that the mind is not the body is illustrated in a backhanded way by Kant's treatment of it (as he found it in Descartes and Leibniz, not James, of course).
Kant did not think that we could explain anything about the nature of the mind, including whether or not it is made out of matter. To make the case for this view, he had to show that all existing arguments that the mind is not material do not work and he set out to do just this in the chapter in the Critique of Pure Reason on the Paralogisms of Pure Reason (1781) (paralogisms are faulty inferences about the nature of the mind). Kant's argument that the Unity Argument does not support dualism is simple. He urges that the idea of unified consciousness being achieved by something that has no parts or components be no less mysterious than its being achieved by a system of components acting together. Remarkably enough, though no philosopher has ever met this challenge of Kant's and no account exists of what an immaterial mind not made out of parts might be like, philosophers continued to rely on the Unity Argument til the 20th century. It may be a bit difficult for us to capture this now but the idea that unified consciousness could not be realized by any system of components, and for an even stronger reason any system of material components, had a strong intuitive appeal for a long time.
The notion that consciousness is unified was also central to one of Kant's own famous arguments, his ‘transcendental deduction of the categories’. In this argument, boiled down to its essentials, Kant claims that to restriction of the various objects of experience together into a single unified conscious representation of the world, something that he simply assumed that we could do, we could probably apply certain concepts to the items in question. In particular we have to apply concepts from each of four fundamental categories of concept: Quantitative, qualitative, relational, and what he called ‘modal’ concepts. Modal conceptual concern of whether an item might exist, does exist, or must exist. Thus, the four kinds of concept are concepts for how many units, what features, what relations to other objects, and what existence statuses are represented in an experience.
It was relational concept that most interested Kant and of relational concepts, he thought the concept of cause-and-effect to be by far the most important. Kant wanted to show that natural science (which for him meant primarily physics) was genuine knowledge (he thought that Hume's sceptical treatment of cause and effect relations challenged this status). He believed that if he could prove that we must tie items in our experience together causally if we are to have a unified awareness of them, he would have put physics back on ‘the secure path upon the paradigms of science’. The details of his argument have exercised philosophers for more than two hundred years. We will not go into them here, but the argument illustrates how central the notion of the unity of consciousness was in Kant's thinking about the mind and its relation to the world.
Although the unity of consciousness had been at the centre of pre-20th century research on the mind, early in the 20th century the notion almost disappeared. Logical atomism in philosophy and behaviourism in psychology were both unsympathetic to the notion. Logical atomism focussed on the atomic elements of cognition (sense data, simple propositional judgments, etc.), rather than on how these elements are tied together to form a mind. Behaviourism urged that we focus on behaviour, the mind being construed either as a myth or of something that we cannot and do not need to study in a science of the human persons. This attitude extended to consciousness, of course. The philosopher Daniel Dennett summarizes the attitude prevalent at the time this way: Consciousness was the last bastion of occult properties, epiphenomena, immeasurable subjective states-in short, the one area of mind best left to the philosophers. Let them make fools of themselves trying to corral the quicksilver of ‘phenomenology’ into a respectable theory.
Theory itself, is consistent with fact or reality, not false or incorrect, but truthful, it is sincerely felt or expressed unforeignly to the essential and exact confronting of rules and senses a governing standard, as stapled or fitted in sensing the definitive criteria of narrowedly particularized possibilities in value as taken by a variable accord with reality. To position of something, as to make it balanced, level or square, that we may think of a proper alignment as something, in so, that one is certain, like trust, another derivation of the same appears on the name is etymologically, or ‘strong seers’. Conformity of fact or actuality of a statement been or accepted as true to an original or standard set theory of which is considered the supreme reality and to have the ultimate meaning, and value of existence. Nonetheless, a compound position, such as a conjunction or negation, whose they the truth-values always determined by the truth-values of the component thesis.
Moreover, science, unswerving exactly to positions of something very well hidden, its nature in so that to make it believed, is quickly and imposes on sensing and responding to the definitive qualities or state of being actual or true, such that as a person, an entity, or an event, that might be gainfully to employ the aggregate of things as possessing actuality, existence, or essence. In other words, in that which objectively and in fact do seem as to be about reality, in fact, the satisfying factions of instinctual needs through awareness of and adjustment to environmental demands. Thus, the act of realizing or the condition of being realized is first, and utmost the resulting infraction of realizing.
Nonetheless, a declaration made to explain or justify action, or its believing desire upon which it is to act, by which the conviction underlying fact or cause, that provide logical sense for a premise or occurrence for logical, rational. According to the act/object analysis of experience, every experience with content involves an object of experience to which an act has related the subject of awareness (the event of experiencing that object). This is meant to apply not only to perceptions, which have material objects (whatever is perceived), also to experiences like hallucinations and dream experiences, which do not. Such experiences nonetheless, appear to represent something, and their objects are supposed to be whatever it is that they represent. Act/object theories may differ on the nature of objects of experience, which have been treated as properties. Meinongian objects (which may not exist or have any form of being), and, more commonly. Private mental entities with sensory qualities. (The term ‘sense-data’ is now usually applied to the later, but has also been used as a general term for objects of sense experiences). Act/object theorists may also differ on the relationship between objects of experience and objects of perception, as for representative realism, objects of perception (of which e are ‘indirectly aware’) are always distinct from objects of experience (of which we are ‘directly aware’). Meinongians, however, can simply treat objects of perception as existing objects of experience
The act/object analysis faces several problems concerning the status of objects of experience. Currently the most common view is that the question of whether two subjects are experiencing the same thing (as opposed to having exactly similar experiences) appears to have an answer only on the assumption that the experiences concerned are perceptions with material objects. Nevertheless, as to the act/object analysis the question must have an answer even when this condition is not satisfied. (The answer is always negative on the sense-datum theory. It could be positive on other versions of the act/object analysis, depending on the facts of the case.)
Reassuringly, the phenomenological argument is not, on reflection, convincing, for granting that any experience appears to present us with an object without accepting that it actually does is easy enough. The semantic argument seemingly relational structure of attributions of experience is a challenge dealt within connection with the adverbial theory. Apparent reference to quantification over objects of experience can be handled b analysing them as reference to experiences themselves tacitly typed according to content.
Analytic mental states have long since been lost in reason. Yet, the premise usually the minor premises, of an argument, use the faculty of reason that arises to engage in dialogue or deliberation. That is, of complete dialectic awareness. To determining or conclude by logical thinking out a solution to the problem, would therefore persuade or dissuade someone with reason that posits of itself with the good sense or justification of reasonability. In which, good causes are simply justifiably to be considered as to think. By which humans seek or attain knowledge or truth. Mere reason is insufficient to convince ‘us’ of its veracity. Still, intuitively there is perceptively welcomed by way of comprehension, as the truth or fact, without the use of the rational process, as one comes to assessing someone’s character, it sublimely configures one consideration, and often with resulting comprehensions, in which it is assessing situations or circumstances and draw sound conclusions into the reign of judgement.
Governing by or being according to reason or sound thinking, in that a reasonable solution to the problem, may as well, in being without bounds of common sense and arriving to some reasonable and fair use of reason, especially to form conclusions, inferences or judgements. In that, all evidential altercates of a confronting argument within the usage of thinking or thought out response to issuing the furthering argumentation to fit or join in the sum parts that are composite to the intellectual faculties, by which case human understanding or the attemptive grasp to its thought, are the resulting liberty encroaching men of zeal, well-meaningly, but without understanding.
Being or occurring in fact or actualizes as having a verifiable existence, real objects, a real illness and, . . . Really true and actual and not imaginary, alleged, or ideal, as people and not ghosts, from which are we to find on practical matters and concerns of experiencing the real world. The surrounding surfaces, might we, as, perhaps attest to this for the first time. Being no less than what they state, we have not taken its free pretence, or affections for a real experience, highly as many may encounter real trouble. This, nonetheless, projects of an existing objectivity in which the world whatever subjectivity or convention of thought or language is or have valuing representation, reckoned by actual power, in that of relating to, or being an image formed by light or another identifiable simulation, that converge in space, the stationary or fixed properties, such as a thing or whole having actual existence. All of which, are accorded a truly factual experience into which the actual attestations have brought to you by the afforded efforts of the imagination.
In a similar fashion, is that, to certain ‘principles of the imagination’ are what explains our beliefs in a world of enduring objects. Experience alone cannot produce that belief, everything we directly perceive in ‘momentary and fleeting’. Whatever our experience is like, no reasoning could be assured of the existence of something independent of our impressions which continues too careful’ and exist when they cease. The series of our constant ly changing sense impressions present us with observable features which Hume calls ‘constancy’ and ‘coherence’, and these naturally operate on the mind in such way as eventually to produce ‘the opinion of a continued and distinct existence’. The explanation is complicated, but it is meant to appeal only to psychological mechanisms which can be discovered by ‘careful and exact experiments, and the observation of those particular effects, which result from [the mindis] different circumstance’s and situation’.
It is to believe, that not only in bodies, but also in persons, or selves, which continue to exist through time. This belief too can be explained only by the operation of certain ‘principles of the imagination’. We never directly perceive anything we can call ourselves: The most we can be aware of in ourselves are our constantly changing, momentary perceptions, not the mind or self which has them. For Hume, nothing really binds the different perceptions together, we are led into the ‘fiction’ that they for a unity only because of the way in which the thoughts of such series of perceptions work upon our minds. ‘The mind is a kind of theatre, where several perceptions successively make their appearance: . . . .There is properly no simplicity in it at one time, nor identity in different, whatever natural propensity we may have to imagine that simplicity and identity. The comparison of the theatre must not mislead us. They are the successive perceptions only, that constitutes the mind’.
Hume is often described as a sceptic in epistemology, largely because of his rejection of the role of reason, as traditionally understood, in the genesis of our fundamental beliefs. That rejection, although allied to the scepticism of antiquity, is only one part of an otherwise positive general theory of human nature which would explain how and why we think and believe and do all the things we do.
Nevertheless, the Kantian epistemological distinction between as thing as it is in itself, and that thing as appearance, or as it is for us. For Kant the thing in itself is the thing as it is intrinsically, that is, the character of the thing as pat from any relation that it happens to stand. The thing for us, or as an appearance, on the one hand, is the thing insofar as it stands in relation to our cognitive faculties and other objects. ‘Now a thing in itself cannot be known through mere relations: And we may therefor conclude that since outer sense gives us nothing but mere relations, that this sense of containing representation, keeps the relation of an object to the subject, and not the inner properties the object in itself’. Kant applies this distinction to the subject’s cognition of itself. Since the subject can know itself only insofar as it can intuit itself, and it can intuit itself only with temporal relations, and thus as it is related to its own self, it represents itself ‘as it appears to itself, not as it is’. Thus, the distinction between what the subject is in itself and what it is for itself arises in Kant insofar as the distinction between what is applied and the subject’s own knowledge of itself.
Hegel begins the transition of the epistemological distinction between what the subject is in itself and what it is for itself into an ontological distinction. Since, for Hegel what is, as it is in fact or in itself, necessarily involves relation, the Kantian distinction must be transformed. Taking his cue from the fact, even for Kant, what the subject is in fact or in itself involve a relation to itself, or self-consciousness. Hegel suggests that the cognition of an entity as for such relations or self- relations do not preclude knowledge of the thing itself. Rather, what an entity intrinsically, or in itself, is best understood for the potentiality of that thing to enter specific explicit relations with itself. Just as for consciousness to be explicitly itself is for it to be for itself by being in relation to itself (i.e., to be explicitly self-conscious), the for-itself of any entity is that entity insofar as it is actually related to itself. The distinction between the entity in itself and the entity for itself may thus take to apply to every entity, and no only to the subject. For example, the seed of a plant is that plant in itself or implicitly, while the mature plant that involves actual relations among the plant’s various organs is the plant ‘for itself’. In Hegel, then, the in itself/for itself distinction becomes universalized, in that it is applied to all entities, and not merely to conscious entities. In addition, the distinction takes on an ontological dimension. While the seed and the mature plant are the same entities, the being in itself of the plant, or the plant as potential adult, is ontologically distinct from the being for itself of the plant, or the actual existing mature organism. At which turn, the distinction retains an epistemological dimension in Hegel, although it import is quite different from that of the Kantian distinction. To know a thing it is necessary to know both the actual, explicit self-relations that are the thing (for being in itself of the thing) and the inherent simple principle of these relations, or the being in itself of the thing, real knowledge, for Hegel, thus consists in a knowledge of the thing as it is in and for itself.
Sartre’s distinction between being in itself and being for itself, which is an entirely ontological distinction with minimal epistemological import, is descended from the Hegelian distinction. Sartre distinguishes between what it is for consciousness to be, i.e., being for itself, and the being of the transcendent being intended by consciousness, i.e., being in itself. Being in itself is marked by the total absence of relation, either with itself or with another. On the other hand, what it is for consciousness to be, being for it self, is marked by self-relation. Sartre posits a ‘pre-reflective Cogito’, such that every consciousness of ‘x’ necessarily involves a ‘non-positional’ consciousness of the consciousness of ‘x’. While in Kant every subject is both in itself, i.e., as it is apart from its relations, and for itself insofar as it is related to itself by appearing to itself, and in Hegel every entity can be considered as both in itself and for itself, in Sartre, to be self related for itself is the distinctive oncological mark of consciousness, while to lack relations or to be in itself is the distinctive ontological mark of non-conscious entities.
Ideally, in theory imagination, a concept of reason that is transcendent but non-empirical as to think os conception of and ideal thought, that potentially or actual exists in the mind as a product exclusive to the mental act. In the philosophy of Plato, an archetype of which a corresponding being in phenomenal reality is an imperfect replica, that also, Hegel’s absolute truth, as the conception and ultimate product of reason (the absolute meaning a mental image of something remembered).
Conceivably, in the imagination the formation of a mental image of something that is or should be perceived as real nor present to the senses. Nevertheless, the image so formed can confront and deal with the reality by using the creative powers of the mind. That is characteristically well removed from reality, but all powers of fantasy over reason are a degree of insanity/still, fancy as they have given a product of the imagination free reins, that is in command of the fantasy while it is exactly the mark of the neurotic that his very own fantasy possesses him.
The totality of all things possessing actuality, existence or essence that exists objectively and in fact based on real occurrences that exist or known to have existed, a real occurrence, an event, i.e., had to prove the facts of the case, as something believed to be true or real, determining by evidence or truth as to do. However, the usage in the sense ‘allegation of fact’, and the reasoning are wrong of the ‘facts’ and ‘substantive facts’, as we may never know the ‘facts’ of the case’. These usages may occasion qualms’ among critics who insist that facts can only be true, but the usages are often useful for emphasis. Therefore, we have related to, or used the discovery or determinations of fast or accurate information in the discovery of facts, then evidence has determined the comprising events or truth is much as ado about their owing actuality. Its opposition forming the literature that treats real people or events as if they were fictional or uses real people or events as essential elements in an otherwise fictional rendition, i.e., of, relating to, produced by, or characterized by internal dissension, as given to or promoting internal dissension. So, then, it is produced artificially than by a natural process, especially the lacking authenticity or genuine factitious values of another than what is or should be.
Essentially, a set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena. Having the consistency of explanatory statements, accepted principles, and methods of analysis, finds to a set of theorems that form a systematic view of a branch in mathematics or extends upon the paradigms of science, the belief or principal that guides action or assists comprehension or judgements, usually by an ascription based on limited information or knowledge, as a conjecture, tenably to assert the creation from a speculative assumption that bestows to its beginning. Theoretically, of, relating to, or based on conjecture, its philosophy is such to accord, i.e., the restriction to theory, not practical theoretical physics, as given to speculative theorizing. Also, the given idea, because of which formidable combinations awaiting upon the inception of an idea, demonstrated as true or is assumed to be shown. In mathematics its containment lies of the proposition that has been or is to be proved from explicit assumption and is primarily with theoretical assessments or hypothetical theorizing than practical considerations the measures its quality value.
Looking back a century, one can see a striking degree of homogeneity among the philosophers of the early twentieth century about the topics central to their concerns. More inertly taken to place, is the apparent obscurity and abstruseness of the concerns, which seem at first glance to be removed from the great debates of previous centuries, between ‘realism’ and ‘idealist’, say, of ‘rationalists’ and ‘empiricist’.
Thus, no matter what the current debate or discussion, the central issue is often without conceptual and contentual representations, that if one is without concept, is without idea, such that in one foul swoop would ingest the mere truth that lies to the underlying paradoxes of why is there something instead of nothing? Whatever it is that makes, what would otherwise be mere utterances and inscriptions into instruments of communication and understanding. This philosophical problem is to demystify this overblowing emptiness, and to relate to what we know of ourselves and the world.
Contributions to this study include the theory of ‘speech arts’, and the investigation of communicable communications, especially the relationship between words and ideas, and words and the world. It is, nonetheless, that which and utterance or sentence expresses, the proposition or claim made about the world. By extension, the content of a predicate that any expression that is capable of connecting with one or more singular terms to make a sentence, the expressed condition that the entities referred to may satisfy, in which case the resulting sentence will be true. Consequently we may think of a predicate as a function from things to sentences or even to truth-values, or other sub-sentential components that contribute to sentences that contain it. The nature of content is the central concern of the philosophy of language.
What some person expresses of a sentence often depends on the environment in which he or she is placed. For example, the disease that may be referred to by a term like ‘arthritis’ or the kind of tree referred as a criterial definition of an ‘oak’, of which, horticulturally I know next to nothing. This raises the possibility of imaging two persons in comparatively different environments, but in which everything appears the same to each of them. The wide content of their thoughts and saying will be different if the situation surrounding them is appropriately different, ‘situation’ may here include the actual objects they perceive, or the chemical or physical kinds of objects in the world they inhabit, or the history of their words, or the decisions of authorities on what counts as an example of some terms thy use. The narrow content is that part of their thought that remains identical, through the identity of the way things appear, no matter these differences of surroundings. Partisans of wide . . . ‘as, something called broadly, content may doubt whether any content is in this sense narrow, partisans of narrow content believe that it is the fundamental notion, with wide content being of narrow content plus context.
All and all, assuming their rationality has characterized people is common, and the most evident display of our rationality is capable to think. This is the rehearsal in the mind of what to say, or what to do. Not all thinking is verbal, since chess players, composers, and painters all think, and there is no deductive reason that their deliberations should take any more verbal a form than their actions. It is permanently tempting to conceive of this activity as for the presence in the mind of elements of some language, or other medium that represents aspects of the world and its surrounding surface structures. Nevertheless, they have attacked the model, notably by Ludwig Wittgenstein (1889-1951), whose influential application of these ideas was in the philosophy of mind. Wittgenstein explores the role that report of introspection, or sensations, or intentions, or beliefs actually play our social lives, to undermine the Cartesian picture that functionally describes the goings-on in an inner theatre of which the subject is the lone spectator. Passages that have subsequentially become known as the ‘rule following’ considerations and the ‘private language argument’ are among the fundamental topics of modern philosophy of language and mind, although their precise interpretation is endlessly controversial.
Effectively, the hypotheses especially associated with Jerry Fodor (1935-), whom is known for the ‘resolute realism’, about the nature of mental functioning, that occurs in a language different from one’s ordinary native language, but underlying and explaining our competence with it. The idea is a development of the notion of an innate universal grammar (Chomsky), in as such, that we agree that since a computer programs are linguistically complex sets of instructions were the relative executions by which explains of surface behaviour or the adequacy of the computerized programming installations, if it were definably amendable and, advisably corrective, in that most are disconcerting of many that are ultimately a reason for ‘us’ of thinking intuitively and without the indulgence of retrospective preferences, but an ethical majority in defending of its moral line that is already confronting ‘us’. That these programs may or may not improve to conditions that are lastly to enhance of the right a type of existence posted exactly to position of something for its nature in so that make it believed, and imposes on seizing the defensive quality value amounts in humanities lesser extensions that embrace one’s riff of necessity to humanities’ suspension to express in the determined qualities.
As of an ordinary language-learning and competence, the hypothesis has not found universal favour, as only ordinary representational powers that by invoking the image of the learning person’s capabilities are apparently whom the abilities for translating are contending of an innate language whose own powers are mysteriously a biological given. Perhaps, the view that everyday attributions of intentionality, beliefs, and meaning to other persons act by means of a tactic use of a theory that enables one to construct these interpretations as s of their doings. We have commonly held the view along with ‘functionalism’, according to which psychological states are theoretical entities, identified by the network of their causes and effects. The theory-theory has different implications, depending upon which feature of theories is being stressed. We may think of theories as capable of formalization, as yielding predictions and, as achieved by a process of theorizing, as answering to empirical evidence that is in principle describable without them, as liable to be overturned by newer and better theories, and so on.
The main problem with seeing our understanding of others as the outcome of a piece of theorizing is the nonexistence of a medium in which we can couch this theory, as the child learns simultaneously the minds of others and the meaning of terms in its native language, is not gained by the tactic use of a ‘theory’, enabling ‘us’ to imply what thoughts or intentions explain their actions, but by realizing the situation ‘in their shoes’ or from their point of view, and by that understanding what they experienced and theory, and therefore expressed. We achieve understanding others when we can ourselves deliberate as they did, and hear their words as if they are our own. The suggestion is a modern development usually associated in the ‘Verstehen’ traditions of Dilthey (1833-1911), Weber (1864-1920) and Collingwood (1889-1943).
We may call any process of drawing a conclusion from a set of premises a process of reasoning. If the conclusion concerns what to do, the process is called practical reasoning, otherwise pure or theoretical reasoning. Evidently, such processes may be good or bad, if they are good, the premises support or even entail the conclusion drawn, and if they are bad, the premises offer no support to the conclusion. Formal logic studies the cases in which conclusions are validly drawn from premises, but little human reasoning is overly of the forms logicians identify. Partly, we are concerned to draw conclusions that ‘go beyond’ our premises, in the way that conclusions of logically valid arguments do not for the process of using evidence to reach a wider conclusion. However, such anticipatory pessimism about the prospects of conformation theory, denying that we can assess the results of abduction as to probability.
Some inciting historians feel that there were four contributions to the theory of probability that overshadowed all the rest. The first was the work of Jacob Bernoulli, and the second De Moivre’s, Doctrine of Chances, the third dealt with Bayes’ Inverse Probability, and the fourth was the outstanding work by LaPlace. In fact, it was LaPlace himself who gave the classic ‘definition’ of probability-if an event can result in ‘n’ equally likely outcomes, then the probability of such an event ‘E’ is the ratio of the number of outcomes favourable to ‘E’ to the total number of outcomes.
A process of reasoning in which a conclusion is drawn from a set of premises usually confined to cases in which the conclusions are supposed in following from the premises, i.e., the inference is logically valid, in that of deductibility in a logically defined syntactic premise but without there being to any reference to the intended interpretation of its theory. Moreover, as we reason we use the indefinite lore or commonsense set of presuppositions about what it is likely or not a task of an automated reasoning project, which is to mimic this causal use of knowledge of the way of the world in computer programs.
Some ‘theories’ usually emerge as a component position, such as those presented by truth-values determined by truth values of a component thesis, in so doing, the imaginative formation of the metal act is or should be perpetuated of the form or actual existence in the mind for being real nor as it presents itself to the senses as for being non-real, supposed truths that are not organized, making the theory difficult to survey or study as a whole. The axiomatic method is an idea for organizing a theory, one in which tries to select from among the supposed truths a small number from which they can see all others to be deductively inferable. This makes the theory moderately tractable since, in a sense, we have contained all truths in those few. In a theory so organized, we have called the few truths from which we have deductively inferred all others ‘axioms’. David Hilbert (1862-1943) had argued that, just as algebraic and differential equations, which we were used to study mathematical and physical processes, could they be made mathematical objects, so axiomatic theories, like algebraic and differential equations, which are means to representing physical processes and mathematical structures could be of investigation.
According to theory, the philosophy of science, is a generalization or set referring to unobservable entities, e.g., atoms, genes, quarks, unconscious wishes. The ideal gas law, for example, refers only to such observables as pressure, temperature, and volume, the ‘molecular-kinetic theory’ refers to molecules and their properties, . . . although an older usage suggests the lack of adequate evidence in support of it (merely a theory), current philosophical usage does in fact follow in the tradition (as in Leibniz, 1704), as many philosophers had the conviction that all truths, or all truths about a particular domain, followed from as few than for being the greater of governing principles, These self-aggrandizing principles, taken to be either metaphysically prior or epistemologically prior or both.
In the first sense, they we took to be entities of such a nature that what exists s ‘caused’ by them. When we took the principles as epistemologically prior, that is, as ‘axioms’, we took them to be either epistemologically privileged, e.g., self-evident, not needing to be demonstrated, or again, included ‘or’, to such that all truths so indeed follow from them, by deductive inferences. Gödel (1984) showed in the spirit of Hilbert, treating axiomatic theories as themselves mathematical objects that mathematics, and even a small part of mathematics, elementary number theory, could not be axiomatized, that more precisely, any class of axioms that is such that we could effectively decide, of any proposition, whether or not it was in that class, would be too small to capture in of the truths.
The notion of truth occurs with remarkable frequency in our reflections on language, thought and action. We are inclined to suppose, for example, that truth is the proper aim of scientific inquiry, that true beliefs help to achieve our goals, that to understand a sentence is to know which circumstances would make it true, that reliable preservation of truth as one argues of valid reasoning, that moral pronouncements should not be regarded as objectively true, and so on. To assess the plausibility of such theses, and to refine them and to explain why they hold (if they do), we require some view of what truth be a theory that would account for its properties and its relations to other matters. Thus, there can be little prospect of understanding our most important faculties in the sentence of a good theory of truth.
The most influential idea in the theory of meaning in the past hundred years is the thesis that the meaning of an indicative sentence is given by its truth-conditions. On this conception, to understand a sentence is to know of its truth-condition. The conception was first clearly formulated by Frége, was developed in a distinctive way by the early Wittgenstein, and is a leading idea of Davidson. The conception has remained so central that those who offer opposing theories characteristically define their position by reference to it.
The conception of meaning as truth-conditions needs not and should not be advanced for being a complete account of meaning. For instance, one who understands a language must have some idea of the range of speech acts conventionally acted by the various types of sentences in the language, and must have some idea of the significance of various kinds of speech acts. The claim of the theorist of truth-conditions should be targeted on the notion of content: If two indicative sentences differ in what they strictly and literally say, then this difference is fully accounted for by the difference in their truth-conditions.
The meaning of a complex expression depends on the meaning of its constituent. This is simply a conscionable statement of what it is for an expression to be semantically complex. It is one initial attraction of the conception of meaning as truth-conditions that it permits a smooth and satisfying account of the way in which the meaning of a complex expression is function of meaning of its constituents. On the truth-conditional conception, to give the meaning of an expression is to state the contribution it makes to the truth-conditions of a sentence in which it occurs. For singular terms-proper names, indexicals, and certain pronouns-this is done by stating the reference of the term in question. For predicates, it is done either by stating the conditions under which the predicate is true of arbitrary objects, or by stating the conditions under which arbitrary atomic sentences containing it is true. The meaning of a sentence-forming operator is given by stating its contribution to the truth-conditions of a complete sentence, as a function of the semantic values of the sentences on which it operates.
Among the many challenges facing the theorist of truth conditions, two are particularly salient and fundamental. First, the theorist has to answer the charge of triviality or vacuity. Second, the theorist must offer an account of what it is for a person’s language to be truly described by a semantic theory containing a given semantic axiom.
We can take the charge of triviality first, since the content of a claim that the sentence ‘Paris is beautiful’ is true and amounts to no more than the claim that Paris is beautiful, we can trivially describe understanding a sentence, if we wish, as knowing its truth-conditions, but this gives us no substantive account of understanding whatsoever. Something other than the grasp of truth conditions must provide the substantive account. The charge rests upon what has been called the redundancy theory of truth, the theory that, is somewhat more discriminatively, Horwich calls the minimal theory of true. The minimal theory states that the concept of truth is exhausted by the fact that it conforms to the equivalence principle, the principle that for any proposition ‘p’. It is true that ‘p’ if and only if ‘p’. Many different philosophical theories of truth will, with suitable qualifications, accept that equivalence principle. The distinguishing feature of the minimal theory is its claim that the equivalence principle exhausts the notion of truth. It is now widely accepted, both by opponents and supporters of truth conditional theories of meaning, that it is inconsistent to accept both the minimal theory of truth and a truth conditional account of meaning. In the claim that the sentence, ‘Paris is beautiful’ is true that Paris is beautiful, it is circular to try to explain the sentence’s meaning under its truth conditions. The minimal theory of truth has been endorsed by Ramsey, Ayer, the later Wittgenstein, Quine, Srawson, Horwich, and -confusingly and inconsistently if this is correct- Frége himself. But is the minimal theory correct?
The minimal theory treats instances of the equivalence principle as definitional truth for a given sentence. But in fact it seems that each instance of the equivalence principle can itself be explained. The truth from which such a condition would occur as:
‘London is beautiful’ is true if and only if London is beautiful.
This would be a pseudo-explanation if the fact that ‘London’ refers to London consists in part in the fact that ‘London is beautiful’ has the truth-condition it does. But that is very implausible: It is, after all, possible to align itself with the name, ‘London’ without understanding the predicate ‘is beautiful’.
The defender of the minimalist theory is likely to say that if a sentence ‘S’ of a foreign language is best translated by our sentencer ‘p’, then the foreign sentence ‘S’ is true if and only if ‘p’. Now the best translation of a sentence must preserve the concepts expressed in the sentence. Constraints involving a general notion of truth are pervasive in a plausible philosophical theory of concepts. It is, for example, a condition of adequacy on an individuating account of any concept that there exits what is called a ‘Determination Theory’ for the account-that is, a specification of how the account contributes to fixing the semantic value of that concept. The notion of a concept’s semantic value is the notion of something that makes a certain contribution to the truth conditions of thoughts in which the concept occurs. But this is to presuppose, than to elucidate, a general notion of truth.
It is also plausible that there are general constraints on the form in Determination Theories, constraints that involve truth which is not derivable from the minimalist’s conception. Supposed that concepts are individuated by their possession condition. One such plausible general constraint is then the requirement that when a thinker forms beliefs involving a concept according to its possession condition, a semantic value belief are assigned to the concept so that the belief is true. Some general principles involving truth can indeed, as Horwich has emphasized, be derived from the equivalence schema using minimal logical apparatus. Consider, for instance, the principle that ‘Paris is beautiful and London is beautiful’ is true if and only if ‘Paris is beautiful’ is true and ‘London is beautiful’ is true. This follows logically from the three instances of the equivalence principle: ‘Paris is beautiful and London is beautiful’ is true if and only if Paris is beautiful and London is beautiful: ‘Paris is beautiful’ is true if and only if Paris is beautiful: And ‘London is beautiful’ is true if and only if London is beautiful. But no logical manipulations of the equivalence schema will allow the derivation of that general constraint governing possession conditions, truth and the assignment of semantic values. That constraint can, of course, be regarded as a further elaboration of the idea that truth is one of the aims of judgement.
What is it for a person’s language to be correctly describable by a semantic theory containing a particular axiom? This question may be addressed at two depths of generality. At the shallower level, the question may take for granted the person’s possession of the concept of conjunction, and be concerned with what has to be true for the axiom to describe his language correctly. At a deeper level, an answer should not duck the issue of what it is to possess the concept. The answers to both questions are of great interest. When a person mans conjunction by ‘and’, he could not formulate the axiom. Even if he can formulate it, his ability to formulate it is not the casual basis of his capacity to hear sentences containing the word ‘and’ as meaning something involving conjunction by sentences he utters containing the word ‘and’. Is it then right to regard a truth theory as part of an unconscious psychological computation, and to regard understanding a sentence involving a particular way of deriving a theorem from a truth theory at some level of unconscious processing? One problem with this is that it is quite implausible that everyone who speaks the same language has to use the same algorithms for computing the meaning of a sentence. In the past thirteen years, a conception has evolved according to which an axiom is true of a person’s language only if there is a common component in the explanation of his understanding of each sentence containing the word ‘and’, a common component that explains why each such sentence is understood as meaning something involving conjunction (Davies, 1987). What conception can also be elaborated in computational terms? It is to suggest for an axiom to be true of a person’s language is for the unconscious mechanisms that produce understanding to draw n the information that a sentence of the form ‘A’ and ‘B’ are true if and only if ‘A’ is true and ‘B’ is true (Peacocke, 1986). Many different algorithms may equally draw on this information. The psychological reality of a semantic theory thus involves, in Marr’s (1982) classification, something intermediate between his level one, the function computed, and his level two, the algorithm by which it is computed. Thus, its conception of the psychological reality of a semantic theory can be applied to syntactic and phonological theories. Theories in semantics, syntax and phonology are not themselves required to specifically particular algorithms that the language user employs. The identification of the particular computational methods employed is a task for psychology. But semantic, syntactic and phonological theorists are answerable to psychological data, and are potentially refutable by them-for these linguistic theories do make commitments to the information drawn upon by mechanisms in the language user.
This answer to the question of what it is for an axiom to be true of a person’s language clearly takes for granted the person’s possession of the concept expressed by the word translated by the axiom. In this example, the information drawn upon is those sentences of the form ‘A’ and ‘B’ are true if and only if ‘A’ is true and ‘B’ is true. This informational content employs, as I, to am adequate, the concept of conjunction used in stating the meaning of sentences containing ‘and’. So the computational answer we have returned needs further elaboration if we are to address the deeper question, which does not want to take for granted possession of the concepts expressed in the language. It is at this point is the theory of linguistic understanding to draw upon a theory of concepts. This is only part of what is involved in the required dovetailing. Given what we have already said about the uniform explanation of the understanding of the various occurrences of a given weird, we should also add that there is a uniform (unconscious, computational) explanation of the language user’s willingness to make the corresponding transition involving the sentence ‘A’ and ‘B’.
Our thinking, and our perceptions of the world about us, is limited by the nature of the language that our culture employs, instead of language possessing, as had previously been widely assumed, much less significant, purely instrumental, function in our living. Human beings do not live in the objective world alone, nor alone in the world social activity as ordinarily understood, but are very much at the mercy of the particular language that has become the medium of expression for their society. It is quite an illusion to imagine that language is merely an incidental means of solving specific problems of communication or reflection. The consideration is that the ‘real world’ is, largely, unconsciously built up on the language habits of the group, we see and hear and otherwise we experience very largely as we do because the language habits of our community predispose certain choices of interpretation.
Such a thing, however, has been notoriously elusive. The ancient idea that truth is some sort of ‘correspondence with reality’ has still never been articulated satisfactorily, and the nature of the alleged ‘correspondence’ and the alleged ‘reality’ remain objectionably obscure. Yet the familiar alternative suggestions that true beliefs are those that are ‘mutually coherent’, or ‘pragmatically useful’, or ‘verifiable in suitable conditions’ has each been confronted with persuasive counterexamples. A twentieth-century departure from these traditional analyses is the view that truth is not a property at all that the syntactic form of the predicate, ‘is true’, distorts its really semantic character, which is not to describe propositions but to endorse them. However, this radical approach is also faced with difficulties and suggests, quasi counter intuitively, that truth cannot have the vital theoretical role in semantics, epistemology and elsewhere that we are naturally inclined to give it. Thus, truth threatens to remain one of the most enigmatic of notions: An explicit account of it can seem essential yet beyond our reach. However, recent work provides some grounds for optimism.
We have based a theory in philosophy of science, is a generalization or set as concerning observable entities, i.e., atoms, quarks, unconscious wish, and so on. The ideal gas law, for example, refers only to such observables as pressure, temperature, and volume, the molecular-kinetic theory refers top molecules and their properties, although an older usage suggests the lack of adequate evidence in support of it (merely a theory), progressive toward its sage; the usage does not carry that connotation. Einstein’s special; Theory of relativity, for example, is considered extremely well founded.
These are two main views on the nature of theories. According to the ‘received view’ theories are partially interpreted axiomatic systems, according to the semantic view, a theory is a collection of models (Suppe, 1974). Under which, some theories usually emerge as exemplifying or occurring in fact, from which are we to find on practical matters and concern of experiencing the real world, nonetheless, that it of supposed truths that are not neatly organized, making the theory difficult to survey or study as a whole. The axiomatic method is an ideal for organizing a theory (Hilbert, 1970), one tries to select from among the supposed truths a small number from which all the others can be seen to be deductively inferable. This makes the theory more tractable since, in a sense, they contain all truth’s in those few. In a theory so organized, they call the few truths from which they deductively infer all others ‘axioms’. David Hilbert (1862-1943) had argued that, just as algebraic and differential equations, which were used to study mathematical and physical processes, could they be made mathematical objects, so we could make axiomatic theories, like algebraic and differential equations, which are means of representing physical processes and mathematical structures, objects of mathematical investigation.
Many philosophers had the conviction that all truths, or all truths about a particular domain, followed from a few principles. These principles were taken to be either metaphysically prior or epistemologically prior or both. In the first sense, we took them to be entities of such a nature that what exists is ‘caused’ by them. When we took the principles as epistemologically prior, that is, as ‘axioms’, we took them to be either epistemologically privileged, i.e., self-evident, not needing to be demonstrated, or again, inclusive ‘or’, to be such that all truths do indeed follow from them, by means of deductive inferences. Gödel (1984) showed in the spirit of Hilbert, treating axiomatic theories as themselves mathematical objects that mathematics, and even a small part. Of mathematics, elementary number theory, could not be axiomatized, that, more precisely, any class of axioms that is such that we could effectively decide, of any proposition, whether or not it was in that class, would be too small to capture all of the truths.
The notion of truth occurs with remarkable frequency in our reflections on language, thought, and action. We are inclined to suppose, for example, that truth is the proper aim of scientific inquiry, that true beliefs help ‘us’ to achieve our goals, that to understand a sentence is to know which circumstances would make it true, that reliable preservation of truth as one argues from premises to a conclusion is the mark of valid reasoning, that we should not regard moral pronouncements as objectively true, and so on. To assess the plausible of such theses, and to refine them and to explain why they hold (if they do), we require some view of what truth be a theory that would account for its properties and its relations to other matters. Thus, there can be little prospect of understanding our most important faculties lacking a good theory of truth.
The nature of the alleged ‘correspondence’ and the alleged ‘reality remains objectivably obscures’. Yet, the familiar alternative suggests, ~ that true beliefs are those that are ‘mutually coherent’, or ‘pragmatically useful’, or ‘they establish by induction of each to a confronted verifiability in some suitable conditions with persuasive counterexamples. A twentieth-century departure from these traditional analyses is the view that truth is not a property at all ~. That the syntactic form of the predicate, ‘is true’, distorts its really semantic character, which is not to describe propositions but to endorse them. Nevertheless, they have also faced this radical approach with difficulties and suggest, a counter intuitively, that truth cannot have the vital theoretical role in semantics, epistemology and elsewhere that we are naturally inclined to give it. Thus, truth threatens to remain one of the most enigmatic of notions, and an explicit account of it can seem essential yet, beyond our reach. However, recent work provides some grounds for optimism.
The belief that snow is white owes its truth to a certain feature of the external world, namely, to the fact that snow is white. Similarly, the belief that dogs bark is true because of the fact that dogs bark. This trivial observation leads to what is perhaps the most natural and popular account of truth, the ‘correspondence theory’, according to which a belief (statement, a sentence, propositions, etc.) as true just in case there exists a fact corresponding to it (Wittgenstein, 1922). This thesis is unexceptionably for finding out whether one should account of truth are that it is clearly compared with the correspondence theory, and that it succeeds in connecting truth with verification. However, if it is to provide a rigorous, substantial and complete theory of truth ~. If it is to be more than merely a picturesque way of asserting all equivalences to the form:
The belief that ‘p’ is ‘true p’.
Then we must supplement it with accounts of what facts are, and what it is for a belief to correspond to a fact, and these are the problems on which the correspondence theory of truth has foundered. For one thing, it is far form clear that reducing ‘the belief achieves any significant gain in understanding that ‘snow is white is true’ to ‘the facts that ‘snow is white’ exists’: For these expressions seem equally resistant to analysis and too close in meaning for one to provide an illuminating account of the other. In addition, the general relationship that holds in particular between the belief that snow is white and the simple fact is, that snow is white, between the belief that dogs bark and the fact that dogs bark, and so on, is very hard to identify. The best attempt to date is Wittgenstein’s (1922) so-called ‘picture theory’, under which an elementary proposition is a configuration of terms, with whatever stare of affairs it reported, as an atomic fact is a configuration of simple objects, an atomic fact corresponds to an elementary proposition (and makes it true) when their configurations are identical and when the terms in the proposition for it to the similarly-placed objects in the fact, and the truth value of each complex proposition the truth values of the elementary ones have entailed. However, even if this account is correct as far as it goes, it would need to be completed with plausible theories of ‘logical configuration’, ‘elementary proposition’, ‘reference’ and ‘entailment’, none of which is easy to come by way of the central characteristic of truth. One that any adequate theory must explain is that when a proposition satisfies its ‘conditions of proof or verification’, then it is regarded as true. To the extent that the property of corresponding with reality is mysterious, we are going to find it impossible to see what we take to verify a proposition should indicate the possession of that property. Therefore, a tempting alternative to the correspondence theory an alternative that eschews obscure, metaphysical concept which explains quite straightforwardly why Verifiability implies, truth is simply to identify truth with verifiability (Peirce, 1932). This idea can take on variously formed. One version involves the further assumption that verification is ‘holistic’, i.e., that of a belief is justified (i.e., turn over evidence of the truth) when it is part of an entire system of beliefs that are consistent and ‘harmonious’ (Bradley, 1914 and Hempel, 1935). We have known this as the ‘coherence theory of truth’. Another version involves the assumption associated with each proposition, some specific procedure for finding out whether one should on sensing and responding to the definitive qualities or stare of being actual or true, such that a person, an entity, or an event, that is actually might be gainfully to employ the totality of things existent of possessing actuality or essence. On this account, to say that a proposition is true is to sa that the appropriate procedure would verify (Dummett, 1979, and Putnam, 1981). From mathematics this amounts to the identification of truth with probability.
The attractions of the verificationist account of truth are that it is refreshingly clear compared with the correspondence theory, and that it succeeds in connecting truth with verification. The trouble is that the bond it postulates between these notions is implausibly strong. We do indeed take verification to indicate truth, but also we recognize the possibility that a proposition may be false in spite of there being impeccable reasons to believe it, and that a proposition may be true although we are not able to discover that it is. Verifiability and ruth are no doubt highly correlated, but surely not the same thing.
A well-known account of truth is known as ‘pragmatism’ (James, 1909 and Papineau, 1987). As we have just seen, the verificationist selects a prominent property of truth and considers it the essence of truth. Similarly, the pragmatist focuses on another important characteristic namely, that true belief is a good basis for action and takes this to be the very nature of truth. We have said that true assumptions were, by definition, those that provoke actions with desirable results. Again, we have an account with a single attractive explanatory feature, but again, it postulates between truth and its alleged analysand then, utility is implausibly close. Granted, true belief tends to foster success, but it happens regularly that actions based on true beliefs lead to disaster, while false assumptions, by pure chance, produce wonderful results.
One of the few uncontroversial facts about truth is that the proposition that snow is white if and only if snow is white, the proposition that lying is wrong is true if and only if lying is wrong, and so on. Traditional theories acknowledge this fact but regard it as insufficient and, as we have seen, inflate it with some further principle of the form, ‘x is true’ if and only if ‘x’ has property ‘p’ (such as corresponding to reality, Verifiability, or being suitable as a basis for action), which is supposed to specify what truth is. Some radical alternatives to the traditional theories result from denying the need for any such further specification (Ramsey, 1927, Strawson, 1950 and Quine, 1990). For example, ne might suppose that the basic theory of truth contains nothing more that equivalences of the form, ‘The proposition that ‘p’ is true if and only if ‘p’ (Horwich, 1990).
This sort of proposal is best presented with an account of the ‘raison de étre’ of our notion of truth, namely that it enables ‘us ’ to express attitudes toward these propositions we can designate but not explicitly formulate. Suppose, for example, they tell you that Einstein’s last words expressed a claim about physics, an area in which you think he was very reliable. Suppose that, unknown to you, his claim was the proposition whose quantum mechanics are wrong. What conclusion can you draw? Exactly which proposition becomes the appropriate object of your belief? Surely not that quantum mechanics are wrong, because you are not aware that is what he said. What we have needed is something equivalent to the infante conjunction:
If what Einstein said was that E = mc2, then E = mc2,
and if that he said as that Quantum mechanics were
wrong, then Quantum mechanics are wrong
. . . . And so on?
That is, a proposition, ‘K’ with the following properties, that from ‘K’ and any further premises of the form. ‘Einstein’s claim was the proposition that p’ you can infer p’. Whatever it is. Now suppose, as the deflationist says, that our understanding of the truth predicate consists in the stimulative decision to accept any instance of the schema. ‘The proposition that ‘p; is true if and only if ‘p’, then we have solved your problem. For ‘K’ is the proposition, ‘Einstein’s claim is true ’, it will have precisely the inferential power that we have needed. From it and ‘Einstein’s claim is the proposition that quantum mechanics are wrong’, you can use Leibniz’s law to infer ‘The proposition that quantum mechanic is wrong is true, which given the relevant axiom of the deflationary theory, allows you to derive ‘Quantum mechanics is wrong’. Thus, one point in favour of the deflationary theory is that it squares with a plausible story about the function of our notion of truth, in that its axioms explain that function without the need for further analysis of ‘what truth ‘is’.
Not all variants of deflationism have this virtue, according to the redundancy performative theory of truth, implicate a pair of sentences, ‘The proposition that ‘p’ is true’ and plain ‘p’s’, has the same meaning and expresses the same statement as one and another, so it is a syntactic illusion to think that p is true’ attributes any sort of property to a proposition (Ramsey, 1927 and Strawson, 1950). Nonetheless, it becomes hard to explain why we are entitled to infer ‘The proposition that quantum mechanics are wrong is true’ form ‘Einstein’s claim is the proposition that quantum mechanics are wrong. ‘Einstein’s claim is true’. For if truth is not property, then we can no longer account for the inference by invoking the law that if ‘x’, appears identical with ‘Y’ then any property of ‘x’ is a property of ‘Y’, and vice versa. Thus the redundancy/performative theory, by identifying rather than merely correlating the contents of ‘The proposition that ‘p’ is true’ and ‘p’, precludes the prospect of a good explanation of one on truth’s most significant and useful characteristics. So restricting our claim to the ineffectually weak, accedes of a favourable Equivalence schematic: The proposition that ‘p’ is true is and is only ‘p’.
Support for deflationism depends upon the possibility of showing that its axiom instances of the equivalence schema non-supplements by any further analysis, will suffice to explain all the central facts about truth, for example, that the verification of a proposition indicates its truth, and that true beliefs have a practical value. The first of these facts follows trivially from the deflationary axioms, for given a deductive assimilation to knowledge of the equivalence of ‘p’ and ‘The proposition that ‘p is true’, any reason to believe that ‘p’ becomes an equally good reason to believe that the preposition that ‘p’ is true. We can also explain the second fact as to the deflationary axioms, but not quite so easily. Consider, to begin with, beliefs of the form:
(B) If I perform the act ‘A’, then my desires will be fulfilled.
Notice that the psychological role of such a belief is, roughly, to cause the performance of ‘A’. In other words, gave that I do have belief (B), then typically.
I will perform the act ‘A’
Notice also that when the belief is true then, given the deflationary axioms, the performance of ‘A’ will in fact lead to the fulfilment of one’s desires, i.e.,
If (B) is true, then if I perform ‘A’, my desires will be fulfilled
Therefore:
If (B) is true, then my desires will be fulfilled
So valuing the truth of beliefs of that form is quite reasonable. Nevertheless, inference derives such beliefs from other beliefs and can be expected to be true if those other beliefs are true. So valuing the truth of any belief that might be used in such an inference is reasonable.
To the extent that they can give such deflationary accounts of all the acts involving truth, then the collection will meet the explanatory demands on a theory of truth of all statements like, ‘The proposition that snow is white is true if and only if snow is white, and we will undermine the sense that we need some deep analysis of truth.
Nonetheless, there are several strongly felt objections to deflationism. One reason for dissatisfaction is that the theory has many axioms, and therefore cannot be completely written down. It can be described as the theory whose axioms are the propositions of the fore ‘p if and only if it is true that p’, but not explicitly formulated. This alleged defect has led some philosophers to develop theories that show, first, how the truth of any proposition derives from the referential properties of its constituents, and second, how the referential properties of primitive constituents are determined (Tarski, 1943 and Davidson, 1969). However, assuming that all propositions including belief attributions remain controversial, law of nature and counterfactual conditionals depends for their truth values on what their constituents refer to. Moreover, there is no immediate prospect of a decent, finite theory of reference, so that it is far form clear that the infinite, that we can avoid list-like character of deflationism.
Another source of dissatisfaction with this theory is that certain instances of the equivalence schema are clearly false. Consider.
(a) THE PROPOSITION EXPRESSED BY THE SENTENCE
IN CAPITAL LETTERS IN NOT TRUE.
Substituting this into the schema one gets a version of the ‘liar’ paradox: Specifically: (b) The proposition that the proposition expressed by the
sentence in capital letters is not true is true if and only
if the proposition expressed by the sentence in capital
letters are not true,
From which a contradiction is easily derivable. (Given (b), the supposition that (a) is true implies that (a) is not true, and the supposition that it is not true that it is.) Consequently, not every instance of the equivalence schema can be included in the theory of truth, but it is no simple matter to specify the ones to be excluded. In "Naming and Necessity" (1980), Kripler gave the classical modern treatment of the topic reference, both clarifying the distinction between names and definite descriptions, and opening the door to many subsequent attempts to understand the notion of reference in terms and an original episode of attaching a name to a subject. Of course, deflationism is far from alone in having to confront this problem.
A third objection to the version of the deflationary theory presented here concerns its reliance on ‘propositions’ as the basic vehicles of truth. It is widely felt that the notion of the proposition is defective and that we should not employ it in semantics. If this point of view is accepted then the natural deflationary reaction is to attempt a reformation that would appeal only to sentences, for example:
‘p’ is true if and only if p.
Nevertheless, this so-called ‘disquotational theory of truth’ (Quine, 1990) has trouble over indexicals, demonstratives and other terms whose referents vary with the context of use. It is not true, for example, that every instance of ‘I am hungry’ is true and only if ‘I am hungry’. There is no simple way of modifying the disquotational schema to accommodate this problem. A possible way of these difficulties is to resist the critique of propositions. Such entities may exhibit an unwelcome degree of indeterminancy, and might defy reduction to familiar items, however, they do offer a plausible account of belief, as relations to propositions, and, in ordinary language at least, we indeed take them to be the primary bearers of truth. To believe a proposition is too old for it to be true. The philosophical problem includes discovering whether belief differs from other varieties of assent, such as ‘acceptance’, discovering to what extent degrees of belief are possible, understanding the ways in which belief is controlled by rational and irrational factors, and discovering its links with other properties, such as the possession of conceptual or linguistic skills. This last set of problems includes the question of whether they have properly said that pre-linguistic infants or animals have beliefs.
Additionally, it is commonly supposed that problems about the nature of truth are intimately bound up with questions as to the accessibility and autonomy of facts in various domains: Questions about whether we can know the facts, and whether they can exist independently of our capacity to discover them (Dummett, 1978, and Putnam, 1981). One might reason, for example, that if ‘t is true’ means’ nothing more than ‘t will be verified’, then certain forms of scepticism, specifically, those that doubt the correctness of our methods of verification, that will be precluded, and that the facts will have been revealed as dependent on human practices. Alternatively, we might say that if truth were an inexplicable, primitive, non-epistemic property, then the fact that ‘t’ is true would be completely independent of ‘us’. Moreover, we could, there, have no reason to assume that the propositions we believe actually have tis property, so scepticism would be unavoidable. In a similar vein, we might think that as special, and perhaps undesirable features of the deflationary approach, is that we have deprived truth of such metaphysical or epistemological implications.
On closer scrutiny, however, it is far from clear that there exists ‘any’ account of truth with consequences regarding the accessibility or autonomy of non-semantic matters. For although we may expect an account of truth to have such implications for facts of the from ‘t is true’, we cannot assume without further argument that the same conclusions will apply to the fact ’t’. For it cannot be assumed that ‘t’ and ‘t are true’ nor, are they equivalent to one and another, explained ‘true’, from which is being employed. Of course, if we have distinguishable truth in the way that the deflationist proposes, then the equivalence holds by definition. However, if reference to some metaphysical or epistemological characteristic has defined truth, then we throw the equivalence schema into doubt, pending some demonstration that the true predicate, in the sense assumed, it will be satisfied insofar, as there are thought to be epistemological problems hanging over ‘t’ that does not threaten ‘t is true’, giving the needed demonstration will be difficult. Similarly, if we so define ‘truth’ that the fact, ‘t’ is felt to be more, or less, independent of human practices than the fact that ‘t is true’, then again, it is unclear that the equivalence schema will hold. It seems. Therefore, that the attempt to base epistemological or metaphysical conclusions on a theory of truth must fail because in any such attempt we will simultaneously rely on and undermine the equivalence schema.
The most influential idea in the theory of meaning in the past hundred yeas is the thesis that meaning of an indicative sentence is given by its truth-conditions. On this conception, to understand a judgment of conviction, as given the responsibility of a sentence, is to know its truth-conditions. The conception was first clearly formulated by Frége (1848-1925), was developed in a distinctive way by the early Wittgenstein (1889-1951), and is a leading idea of Davidson (1917-). The conception has remained so central that those who offer opposing theories characteristically define their position by reference to it.
The conception of meaning as truth-conditions needs not and should not be advanced as a complete account of meaning. For instance, one who understands a language must have some idea of the range of speech acts conventionally performed by the various types of a sentence in the language, and must have some idea of the significance of various kinds of speech acts. We should moderately target the claim of the theorist of truth-conditions on the notion of content: If two indicative sentences differ in what they strictly and literally say, then the difference accounts for this difference in their truth-conditions. Most basic to truth-conditions is simply of a statement that is the condition the world must meet if the statement is to be true. To know this condition is equivalent to knowing the meaning of the statement. Although this sounds as if it gives a solid anchorage for meaning, some security disappears when it turns out that repeating the very same statement can only define the truth condition, as a truth condition of ‘snow is white’ is that snow is white, the truth condition of ‘Britain would have capitulated had Hitler invaded’ is the Britain would have capitulated had Hitler invaded. It is disputed wether. This element of running-on-the-spot disqualifies truth conditions from playing the central role in a substantive theory of meaning. The view has sometimes opposed truth-conditional theories of meaning that to know the meaning of a statement is to be able to use it in a network of inferences.
Whatever it is that makes, what would otherwise be mere sounds and inscriptions into instruments of communication and understanding. The philosophical problem is to demystify this power, and to relate it to what we know of ourselves and the world. Contributions to the study include the theory of ‘speech acts’ and the investigation of communication and the relationship between words and ideas and the world and surrounding surfaces, by which some persons express by a sentence often vary with the environment in which he or she is placed. For example, the disease I refer to by a term like ‘arthritis’ or the kind of tree I call an ‘oak’ will be defined by criteria of which I know next to nothing. The raises the possibility of imagining two persons in moderate differently environmental, but in which everything appears the same to each of them, but between them they define a space of philosophical problems. They are the essential components of understanding nd any intelligible proposition that is true can be understood. Such that which an utterance or sentence expresses, the proposition or claim made about the world may by extension, the content of a predicated or other sub-sentential component is what it contributes to the content of sentences that contain it. The nature of content is the cental concern of the philosophy of language.
In particularly, the problems of indeterminancy of translation, inscrutability of reference, language, predication, reference, rule following, semantics, translation, and the topics referring to subordinate headings associated with ‘logic’. The loss of confidence in determinate meaning (from each individualized decoding is another individual encoding) is an element common both to postmodern uncertainties in the theory of criticism, and to the analytic tradition that follows writers such as Quine (1908-). Still it may be asked, why should we suppose that we should account fundamental epistemic notions for in behavioural terms what grounds are there for assuming ‘p knows p’ is a matter of the status of its statement between some subject and some object, between nature and its mirror? The answer is that the only alternative might be to take knowledge of inner states as premises from which we have normally inferred our knowledge of other things, and without which we have normally inferred our knowledge of other things, and without which knowledge would be ungrounded. However, it is not really coherent, and does not in the last analysis make sense, to suggest that human knowledge have foundations or grounds. We should remember that to say that truth and knowledge ‘can only be judged by the standards of our own day’ which is not to say, that it is less important, or ‘more ‘cut off from the world’, that we had supposed. It is just to say, that nothing counts as justification, unless by reference to what we already accept, and that there is no way to get outside our beliefs and our language to find some test other than coherence. The characterlogical characteristic is that the professional philosophers have thought it might be otherwise, since the body has haunted only them of epistemological scepticism.
What Quine opposes as ‘residual Platonism’ is not so much the hypostasising of nonphysical entities as the notion of ‘correspondence’ with things as the final court of appeal for evaluating present practices. Unfortunately, Quine, for all that it is incompatible with its basic insights, substitutes for this correspondence to physical entities, and specially to the basic entities, whatever they turn out to be, of physical science. Nevertheless, when we have purified their doctrines, they converge on a single claim ~, that no account of knowledge can depend on the assumption of some privileged relations to reality. Their work brings out why an account of knowledge can amount only to a description of human behaviour.
What, then, is to be said of these ‘inner states’, and of the direct reports of them that have played so important a role in traditional epistemology? For a person to feel is nothing else than for him to be able to make a certain type of non-inferential report, to attribute feelings to infants is to acknowledge in them latent abilities of this innate kind. Non-conceptual, non-linguistic ‘knowledge’ of what feelings or sensations is like is attributively to beings from potential membership of our community. We comment upon infants and the more attractive animals with having feelings based on that spontaneous sympathy that we extend to anything humanoid, in contrast with the mere response to stimuli, attributed to photoelectric cells and to animals about which no one feels sentimentally. Assuming moral prohibition against hurting infants is consequently wrong and the better-looking animals are that those moral prohibitions grounded’ in their possession of feelings. The relation of dependence is really the other way round. Similarly, we could not be mistaken in assuming a four-year-old child has knowledge, but no one-year-old, any more than we could be mistaken in taking the word of a statute that eighteen-year-old can marry freely but seventeen-year-old cannot. There is no more ‘ontological ground’ for the distinction that may suit ‘us’ to make in the former case than in the later. Again, such a question as ‘Are robots’ conscious?’ Calling for a decision on our part whether or not to treat robots as members of our linguistic community. All this is a piece with the insight brought intro philosophy by Hegel (1770-1831), that the individual apart from his society is just another animal.
Willard van Orman Quine, the most influential American philosopher of the latter half of the 20th century, when after the wartime period in naval intelligence, punctuating the rest of his career with extensive foreign lecturing and travel. Quine’s early work was on mathematical logic, and issued in ‘A System of Logistic’ (1934), ‘Mathematical Logic’ (1940), and ‘Methods of Logic’ (1950), whereby it was with the collection of papers from a “Logical Point of View” (1953) that his philosophical importance became widely recognized. Quine’s work dominated concern with problems of convention, meaning, and synonymy cemented by “Word and Object” (1960), in which the indeterminancy of radical translation first takes centre-stage. In this and many subsequent writings Quine takes a bleak view of the nature of the language with which we ascribe thoughts and beliefs to ourselves and others. These ‘intentional idioms’ resist smooth incorporation into the scientific world view, and Quine responds with scepticism toward them, not quite endorsing ‘eliminativism’, but regarding them as second-rate idioms, unsuitable for describing strict and literal facts. For similar reasons he has consistently expressed suspicion of the logical and philosophical propriety of appeal to logical possibilities and possible worlds. The languages that are properly behaved and suitable for literal and true descriptions of the world happen to those within the fields that draw upon mathematics and science. We must take the entities to which our best theories refer with full seriousness in our ontologies, although an empiricist. Quine thus supposes that science requires the abstract objects of set theory, and therefore exist. In the theory of knowledge Quine associated with a ‘holistic view’ of verification, conceiving of a body of knowledge as for a web touching experience at the periphery, but with each point connected by a network of relations to other points.
They have also known Quine for the view that we should naturalize, or conduct epistemology in a scientific spirit, with the object of investigation being the relationship, in human beings, between the inputs of experience and the outputs of belief. Although we have attacked Quine’s approaches to the major problems of philosophy as betraying undue ‘scientism’ and sometimes ‘behaviourism’, the clarity of his vision and the scope of his writing made him the major focus of Anglo-American work of the past forty years in logic, semantics, and epistemology. And the works cited his writings’ cover “The Ways of Paradox and Other Essays” (1966), “Ontological Relativity and Other Essays” (1969), “Philosophy of Logic” (1970), “The Roots of Reference” (1974) and “The Time of My Life: An Autobiography” (1985).
Coherence is a major player in the theatre of knowledge. There are cogence theories of belief, truth and justification, as these are to combine themselves in the various ways to yield theories of knowledge coherence theories of belief are concerned with the content of beliefs. Consider a belief you now have, the beliefs that you are reading a page in a book, in so, that what makes that belief the belief that it is? What makes it the belief that you are reading a page in a book than the belief that you have a creature of some sort in the garden?
One answer is that the belief has a coherent place or role in a system of beliefs, perception or the having the perceptivity that has its influence on beliefs. As, you respond to sensory stimuli by believing that you are reading a page in a book than believing that you have some sorted creature in the garden. Belief has an influence on action, or its belief is a desire to act, if belief will differentiate the differences between them, that its belief is a desire or if you were to believe that you are reading a page than if you believed in something about a creature. Sortal perceptivals hold accountably the perceptivity and action that are indeterminate to its content if its belief is the action as if stimulated by its inner and latent coherence in that of your belief, however. The same stimuli may produce various beliefs and various beliefs may produce the same action. The role that gives the belief the content it has is the role it plays upon a network of relations to other beliefs, some latently causal than others that relate to the role in inference and implication. For example, I infer different things from believing that I am reading a page in a book than from any other belief, justly as I infer about other beliefs form.
The input of perceptibility and the output of an action supplement the central role of the systematic relations the belief has to other beliefs, but the systematic relations give the belief the specific contentual representation it has. They are the fundamental source of the content of belief. That is how coherence comes in. A belief has the representational content by which it does because of the way in which it coheres within a system of beliefs (Rosenberg, 1988). We might distinguish weak coherence theories of the content of beliefs from stronger coherence theories. Weak coherence theories affirm that coherence is one determinant of the representation given that the contents are of belief. Strong coherence theories of the content of belief affirm that coherence is the sole determinant of the contentual representations of belief.
When we turn from belief to justification, we confront a similar group of coherence theories. What makes one belief justified and another not? Again, there is a distinction between weak and strong theoretic principles that govern its theory of coherence. Weak theories tell ‘us’ that the way in which a belief coheres with a background system of beliefs is one determinant of justification, other typical determinants being perception, memory, and intuitively strong theories, or dominant projections are in coherence to justification as solely a matter of how a belief coheres with a system of latent hierarchal beliefs. There is, nonetheless, another distinction that cuts across the distinction between weak and strong coherence theories between positive and negative coherence theory (Pollock, 1986). A positive coherence theory tells ‘us’ that if a belief coheres with a background system of belief, then the belief is justifiable. A negative coherence theory tells ‘us’ that if a belief fails to cohere with a background system of beliefs, then the belief is not justifiable. We might put this by saying that, according to the positivity of a coherence theory, coherence has the power to produce justification, while according to its being adhered by negativity, the coherence theory has only the power to nullify justification.
Least of mention, a strong coherence theory of justification is a formidable combination by which a positive and a negative theory tell ‘us’ that a belief is justifiable if and only if it coheres with a background system of inter-connectivity of beliefs. Coherence theories of justification and knowledge have most often been rejected for being unable to deal with an accountable justification toward the perceptivity upon the projection of knowledge (Audi, 1988, and Pollock, 1986), and, therefore, considering a perceptual example that will serve as a kind of crucial test will be most appropriate. Suppose that a person, call her Julie, and works with a scientific instrumentation that has a gauging measure upon temperatures of liquids in a container. The gauge is marked in degrees, she looks at the gauge and sees that the reading is 105 degrees. What is she justifiably to believe, and why? Is she, for example, justified in believing that the liquid in the container is 105 degrees? Clearly, that depends on her background beliefs. A weak coherence theorist might argue that, though her belief that she sees the shape 105 is immediately justified as direct sensory evidence without appeal to a background system, the belief that the location in the container is 105 degrees results from coherence with a background system of latent beliefs that affirm to the shaping perceptivity that its 105 as visually read to be 105 degrees on the gauge that measures the temperature of the liquid in the container. This, nonetheless, of a weak coherence view that combines coherence with direct perceptivity as its evidence, in that the foundation of justification, is to account for the justification of our beliefs.
A strong coherence theory would go beyond the claim of the weak coherence theory to affirm that the justification of all beliefs, including the belief that one sees the shaping to sensory data that holds accountable a measure of 105, or even the more cautious belief that one sees a shape, resulting from the perceptivals of coherence theory, in that it coheres with a background system. One may argue for this strong coherence theory in several different ways. One line or medium through which to appeal to the coherence theory of contentual representations. If the content of the perceptual belief results from the relations of the belief to other beliefs in a network system of beliefs, then one may notably argue that justification thoroughly rests upon the resultants’ findings in relation to the belief been no other than the beliefs of a furthering network system of coordinate beliefs. In face value, the argument for the strong coherence theory is that without any assumptive grasp for reason, in that the coherence theories of content are directed of beliefs and are supposing causes that only produce of a consequent, of which we already expect. Consider the very cautious belief that I see a shape. How could the justification for that perceptual belief be an existent result that they characterize of its material coherence with a background system of beliefs? What might the background system of expression that ‘we’ would justify that belief? Our background system contains a simple and primal theory about our relationship to the world and surrounding surfaces that we perceive as it is or should be believed. To come to the specific point at issue, we believe that we can tell a shape when we see one, completely differentiated its form as perceived to sensory data, that we are to trust of ourselves about such simple matters as wether we see a shape before ‘us’ or not, as in the acceptance of opening to nature the inter-connectivity between belief and the progression through which we acquire from past experiential conditions of application, and not beyond deception. Moreover, when Julie sees the believing desire to act upon what either coheres with a weak or strong coherence of theory, she shows that its belief, as a measurable quality or entity of 105, has the essence in as much as there is much more of a structured distinction of circumstance, which is not of those that are deceptive about whether she sees that shape or sincerely does not see of its shaping distinction, however. Light is good, and the numeral shapes are large, readily discernible and so forth. These are beliefs that Julie has single handedly authenticated reasons for justification. Her successive malignance to sensory access to data involved is justifiably a subsequent belief, in that with those beliefs, and so she is justified and creditable.
The philosophical problems include discovering whether belief differs from other varieties of assent, such as ‘acceptance’ discovering to what extent degrees of belief is possible, understanding the ways in which belief is controlled by rational and irrational factors, and discovering its links with other properties, such as the possession of conceptual or linguistic skills. This last set of problems includes the question of whether we have properly said that pre-linguistic infants or animals have beliefs.
Thus, we might think of coherence as inference to the best explanation based on a background system of beliefs, since we are not aware of such inferences for the most part, we must interpret the inferences as unconscious inferences, as information processing, based on or accessing the background system that proves most convincing of acquiring its act and used from the motivational force that its underlying and hidden desire are to do so.
Inference to the best explanation, can justify beliefs about the external world, the past, theoretical entities in science, and even the future. Consider belief about the external world and assume that we know what we do about the external world through our knowledge of our subjective and fleeting sensations. It seems obvious that we cannot deduce any truths about the existence of physical objects from truths describing the character of our sensations. But neither can we observe a correlation between sensations and something other than sensations since by hypothesis all we ever have to rely on ultimately is knowledge of our sensation. Nevertheless, we may be abler to posit physical objects as the best explanation for the character and order of our sensations. In this way, various hypotheses about the past might best explain present memory, theoretical postulates in physics might best explain phenomena in the macro-world, and it is even possible that our access to the future is through universal laws formulated to explain past observations. But what is the form of an inference to the best explanation?
It is natural to desire a better characterization of inference, but attempts to do so by constructing a fuller psychological explanation fail to comprehend the grounds on which inferences will be objectively valid -a point elaborately made by Frége. And attempts to understand the nature of inference better though the device of the representation of inference by formal-logical calculations or derivations. (1) Leave us puzzled about the relation of formal-logical derivations to the informal inferences they are supposed to represent or reconstruct, and (2) leaves us worried about the sense of such formal derivations. Are these derivations inferences? And are not informal inferences needed to apply the rules governing the constructions of formal derivation (inferring that this operation is an application of that formal rule?). It is usual to find it said that, an inference is a (perhaps very complex) act of thought by virtue of which act (1) I pass from a set of one or more propositions or statements to a proposition or statement and (2) it appears that the latter are true if the former is or are. This psychological characterization has had to encounter the literature under more or less inessential variations. And attempts to understand the nature of inference through the device of the representation of inference by formal-logical calculations or derivations better. Are such that these derivation’s inferences? And aren’t informal inferences needed to apply the rules governing the constructions of formal derivations (inferring that this operation in an application of that formal rule)? These are concerns cultivated by, for example, Wittgenstein.
Coming up with an adequate characterization of inference -and even working out what would count as an adequate characterization is a hard and hardly near a solved philosophical problem.
Let us suppose that there is some property ‘A’ pertaining to an observational or experimental situation, and that out of several of observed instances of ‘A’, some fraction m/n (possibly equal to 1) has also been instances of some logically independent property ‘B’. Suppose further that the background circumstances not specified in these descriptions have been varied to a substantial degree and that there is no collateral information available concerning the frequency of ‘B’s’ among ‘A’s’ or concerning causal or nomological connections between instances of ‘A’ and instances of ‘B’.
In this situation, an enumerative or instantial inductive inference would move from the premise that m/n of observed ‘A’s’ are ‘B’s’ to the conclusion that approximately m/n of all ‘A’s’ are ‘B’s’. (The usual probability qualification will be assumed to apply to the inference, than being part of the conclusion.) The class of ‘A’s’ should be taken to include not only unobserved ‘A’s’ and future ‘A’s, bu also possible or hypothetical ‘A’s’. (An alternative conclusion would concern the probability or likelihood of succeeding observations, ‘A’ being a ‘B’.
The traditional or Humean problem of induction, often called simply the problem of induction, is the problem of whether and why inferences that fit this schema should be considered rationally acceptable or justified from an epistemic or cognitive standpoint, i.e., whether and why reasoning in this way is likely to lead to true claims about the world. Is there any sort of argument or rationale that can be offered for thinking that conclusions reached in this way are likely to be true if the corresponding premiss is true-or, even that their chances of truth are significantly enhanced?
Once, again, this issue deals explicitly with cases where all observed ‘A’s’ are ‘B’s’ and where ‘A’ is claimed to be the cause of ‘B’, but his argument applies just as well to the more general case. Hume’s conclusion is entirely negative and sceptical as inductive inferences are not rationally justified, but are instead, there result of an essentially a-rational process, custom or habit. Hume challenges the proponents of induction to supply a cogent line of reasoning that leads from an inductive premise to the corresponding conclusion and offers an extremely influential argument as a dilemma (sometimes called ‘Hume’s fork’) to show that there can be no such reasoning. Such reasoning would, he argues, have to be either deductively demonstrative reasoning concerning relations of ideas or ‘experimental’ (i.e., empirical) reasoning concerning matters of fact or existence. It cannot be the former, because all demonstrative reasoning relies on the avoidance of contradiction, and it is not as contradiction to suppose that ‘the course of nature may change’, that an order observed in the past will not continue in the future, and it cannot be the latter, since any empirical argument would appeal to the success of such reasoning in previous experience, and the justifiability of generalizing from previous experience is precisely what is at issue-so that any such appeal would be question-begging. Hence concludes. There can be no such reasoning.
When one present such an inference in ordinary discourse it often seems to have the following form:
(1) O is the case.
(2) If ‘E’ had been the case O is what we would expect.
(3) ‘E’ was the case.
This is the argument form that Peirce called hypothesis or abduction. That is of saying, which we typically derive prediction from hypotheses and establish whether they are satisfied, that only an account of induction leaves unanswered two prior questions: How do we arrive at the hypotheses in the first place? And on what basis do we decide which hypotheses are worth testing? These questions concern the logic of discovery or, in Charles S. Peirce’s terminology, abduction. Many empiricist philosophers have denied that there is a logic (as opposed to a psychology) of discovery. Peirce, and followers such as N.R. Hanson, insisted that there is a logic of abduction.
The logic of abduction thus investigates the norms employed in deciding whether a hypothesis is worth testing a given stage of inquiry, and the norms influencing how we should retain the key insights of rejected theories in formulating their successors.
Again, to consider a very simple example, we might upon coming across one’s footprints on a beach, reason to the conclusion that a person walked along the beach recently by noting walking along the beach one would expect to find just such footprints.
But is abduction a legitimate form of reasoning? Obviously, if the conditionals in (2) read as a material conditional such arguments would be hopelessly bad. Since the proposition that ‘E’ materially implies O is entailed by O, there would always be many competing inferences to the best explanation and non of them seem to lend even self-evident support to its conclusion. The conditionals we employ in ordinary discourse, however, are seldom, if ever, material conditionals. The vast majority of ‘I. Then . . . ‘ statements may not be truth-functionally complex. Rather, they seem to assert a connection of some sort between the states of affairs referred to in the antecedent (after the ‘if’) and in the consequent (after the ‘if’) and in the consequent (after the ‘if’). Perhaps the argument for more plausibility, if the conditional is read in this more natural way. But consider an alterative footprints explanation:
(1) There are footprints on the beach.
(2) If cows wearing boots had walked along the beach recently one would expect to find such footprints.
Therefore, there is a high probability that:
(3) Cows wearing boots walked along the beach recently.
This inference has precisely the same form as the earlier inference the conclusion that people walked along the beach recently and its premisses are just as true, but we would have no doubt concerning both the conclusion and the inference as simply silly. If we are to distinguish between legitimate and illegitimate reasoning to the best explanation, it seems that we need a more sophisticated model of the argument form. It seems that in reasoning to an explanation we need criteria for choosing between alternative explanations. If reasoning to the best explanation is to constitute a genuine alternative to inductive reasoning, it is important that these criteria not be implicit premisses that will convert our argument into an inductive argument. Thus, for example, if of this reason we conclude that people rather than cows walked along the beach are only that we are implicitly relying on the premiss that footprints of this sort are usually produced by people, then it is certainly tempting to suppose that our inference to the best explanation was really a disguised inductive inference of the form:
(1) Most footprints are produced by people.
(2) Here are footprints.
Therefore probably
(3) These footprints were produced by people.
If we follow the suggestion made above, we might construe the form of reasoning to the best explanation as follows:
(1) O (a description of some phenomenon).
(2) Of the set of available and competing explanation
E1, E2 . . . En capable of explaining O, E1 is the best according to the correct criteria for choosing among potential explanations.
Therefore probably,
(3) E1.
The model of explanation must be filled, of course, we need to know what the relevant criteria are for choosing among alternative explanations. Perhaps, the ingle most common virtue of explanation cited by philosophers is simplicity. Sometimes simplicity may be understood as for the number of things or events that explanation commits one to. Sometimes the crucial question concerns the number of kinds of things that theory commits one to.
Explanations are also sometimes taken to be more plausible the more explanatory ‘power’ they have. This power is usually defined as the number of a thing or more likely, the number of kinds of things, that they can explain. Thus, Newtonian mechanics were so attractive, the argument goes, partly because of the range of phenomena the theory could explain.
The familiarity of an explanation for the resemblance to already accepted kinds of explanation, in addition that now and again are implicated as a reason for preferring that explanation be for no less than the familiar kinds of explanation. So, if one provides a kind of evolutionary explanation for the disappearance of one’s organ in a creature, should look more favourably on a similar sort of explanation for the disappearance of another organ.
Alternative qualifications may use criterions’ in choosing among varying explanations, and there are many other candidates. But in evaluation the claim that inference to the best explanation constitutes a legitimate and independent argument form, one must explore the argument form, one need explore the question of whether it is a contingent fact that, at least, most phenomenon’s explanations and that explanations that satisfy a given criterion, simplicity, for example, is more likely to be correct. Here it might be pleasant (for scientists and writers of textbooks) if the reasoning to the explanation relies very much criteria. It seems that one cannot without circularity of reasoning to be of explanation to discover that reliance on such criteria is safe. But if one has some independent was of discovering that simple, powerful, familiar explanations are more often correct, then why should we think that reasoning to the best explanation is an independent source of information about the world? Why should we not conclude that it would be more perspicuous to represent reasoning this way?
(1) Most phenomena have the simplest, most powerful,
Familiar explanations available.
(2) Here is an observed phenomenon, and E1 is the simplest, most powerful, familiar explanation available.
Therefore, probably,
(3) This is to be explained by E1.
But the above is simply an instance of familiar inductive reasoning.
One might object to such an account on the grounds that not all justifiable inferences are self-explanatory, and more generally, the account of coherence may, at best, is ably successful to competitions that are based on background systems (BonJour, 1985, and Lehrer, 1990). The belief that one sees a shape competes with the claim that one does not, with the claim that one is deceived, and other sceptical objections. The background system of beliefs informs one that one is acceptingly trustworthy and enables one to meet the objections. A belief coheres with a background system just in case it enables one to meet the sceptical objections and in the way justifies one in the belief. This is a standard strong coherence theory of justification (Lehrer, 1990).
Illustrating the relationship between positive and negative coherence theories for the standard coherence theory is easy. If some objection to a belief cannot be met as the background system of beliefs of a person, then the person is not justified in that belief. So, to return to Julie, suppose that she has been told that a warning light has been installed on her gauge to tell her when it is not functioning properly and that when the red light is on, the gauge is malfunctioning. Suppose that when she sees the reading of 105, she also sees that the red light is on. Imagine, finally, that this is the first time the red light has been on, and, after years of working with the gauge, Julie, who has always placed her trust in the gauge, believes what the gauge tells her, that the liquid in the container is at 105 degrees. Though she believes what she reads is at 105 degrees is not a justified belief because it fails to cohere with her background belief that the gauge is malfunctioning. Thus, the negative coherence theory tells ‘us’ that she is not justified in her belief about the temperature of the contents in the container. By contrast, when we have not illuminated the red light and the background system of Julie that tells her that under such conditions that gauge is a trustworthy indicator of the temperature of the liquid in the container, then she is justified. The positive coherence theory tells ‘us’ that she is justified in her belief because her belief coheres with her background system of Julie lets it be known that she, under such conditions gauges a trustworthy indicant of temperature characterized or identified in respect of the liquid in the container, then she is justified. The positive coherence theory tells ‘us’ that she is justified in her belief because her belief coheres with her background system continues as a trustworthy system.
The foregoing sketch and illustration of coherence theories of justification have a common feature, namely, that they are what we have called inter-naturalistic theories of justification what makes of such a view are the absence of any requirement that the person for whom the belief is justified have any cognitive access to the relation of reliability in question. Lacking such access, such a person will usually, have no reason for thinking the belief is true or likely to be authenticated, but will, on such an account, is nonetheless to appear epistemologically justified in accepting it. Thus, such a view arguably marks a major break from the modern epistemological traditions, which identifies epistemic justification with having a reason, perhaps even a conclusive reason, for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
They are theories affirming that coherence is a matter of internal relations between beliefs and that justification is a matter of coherence. If, then, justification is solely a matter of internal relations between beliefs, we are left with the possibility that the internal relations might fail to correspond with any external reality. How, one might have an objection, can a completely internal subjective notion of justification bridge the gap between mere true belief, which might be no more than a lucky guess, and knowledge, which we must ground in some connection between internal subjective conditions and external objective realities?
The answer is that it cannot and that we have required something more than justified true belief for knowledge. This result has, however, been established quite apart from consideration of coherence theories of justification. What we have required maybe put by saying that the justification that one must be undefeated by errors in the background system of beliefs. Justification is undefeated by errors just in case any correction of such errors in the background system of belief would sustain the justification of the belief based on the corrected system. So knowledge, on this sort of positivity is acclaimed by the coherence theory, which is the true belief that coheres with the background belief system and corrected versions of that system. In short, knowledge is true belief plus justification resulting from coherence and undefeated by error (Lehrer, 1990). The connection between internal subjective conditions of belief and external objectivity are from which reality’s result from the required correctness of our beliefs about the relations between those conditions and realities. In the example of Trust, she believes that her internal subjectivity to conditions of sensory data in which we have connected the experience and perceptual beliefs with the external objectivity in which reality is the temperature of the liquid in the container in a trustworthy manner. This background belief is essential to the justification of her belief that the temperature of the liquid in the container is 105 degrees, and the correctness of that background belief is essential to the justification remaining undefeated. So our background system of beliefs contains a simple theory about our relation to the external world that justifies certain of our beliefs that cohere with that system. For instance, such justification to convert to knowledge, that theory must be sufficiently free from error so that they have sustained the coherence in corrected versions of our background system of beliefs. The correctness of the simple background theory provides the connection between the internal condition and external reality.
Coherence is a major participant in the theatre of knowledge that coherence theories of belief, truth and justification are combined in ways to yield theories of knowledge. Coherence theories of belief are concerned with the content of beliefs, justly as a belief you now have, the beliefs that you are reading a page in a book, making that belief the belief that it is? Particularly, is the belief from which a coherent system of beliefs has an influence on beliefs. Belief has an influence on action. You will act differently if you believe that you are reading a page than if you believe something about whatever bring to a possibility. Perception and action undermine the content of belief, however. The same stimuli may produce various beliefs and various beliefs may produce the same action. The role that gives the belief the content it has is the role it plays within a network of relations to other beliefs, the role in reference and implication, for example, I infer different things from believing that I am reading a page in a book than from any other belief, just as I infer that belief from different things than I infer other beliefs from, but the systematic relations give the belief the specific content it has.
The coherence theory of truth arises naturally out of a problem raised by the coherence theory of justification. The problem is that anyone seeking to determine whether she has knowledge is confined to the search for coherence among her beliefs. The sensory experiences have been deadening til their representation has been exemplified as some perceptual belief. Beliefs are the engines that pull the train of justification. Nevertheless, what assurance do we have that our justification is based on true beliefs? What justification do we have that any of our justifications are undefeated? The fear that we might have none, that our beliefs might be the artifacts of some deceptive demon or scientist, leads to the quest to reduce truth to some form, perhaps an idealized form, of justification (Rescher, 1973, and Rosenberg, 1980). That would close the threatening sceptical gap between justification and truth. Suppose that a belief is true if and only if it is justifiable of some person. For such a person there would be no gap between justification and truth or between justification and undefeated justification. Truth would be coherence with some ideal background system of beliefs, perhaps one expressing a consensus among systems or some consensus among belief systems or some convergence toward a consensus. Such a view is theoretically attractive for the reduction it promises, but it appears open to profound objectification. One is that there is a consensus that we can all be wrong about at least some matters, for example, about the origins of the universe. If there is a consensus that we can all be wrong about something, then the consensual belief system rejects the equation of truth with the consensus. Consequently, the equation of truth with coherence with a consensual belief system is itself incoherently.
Coherence theories of the content of our beliefs and the justification of our beliefs themselves cohere with our background systems but coherence theories of truth do not. A defender of coherentism must accept the logical gap between justified belief and truth, but may believe that our capacities suffice to close the gap to yield knowledge. That view is, at any rate, a coherent one.
What makes a belief justified and what makes a true belief knowledge? Thinking that whether a belief deserves one of these appraisals is non-synthetically depending on what causal subject to has the belief. In recent decades several epistemologists have pursed this plausible idea with a variety of specific proposals. Some causal theories of knowledge have it that a true belief that ‘p’ is knowledge just in case it has the right sort of causal connection to the fact that ‘p’. Such a criterion can be applied only to cases where the fact that ‘p’ is a sort that can reach causal relations, this seems to exclude mathematically and other necessary facts and perhaps any fact expressed by a universal generalization, and proponents of this sort of criterion have usually of this sort of criterion have usually supposed that it is limited to perceptual knowledge of particular facts about the subject’s environment.
For example, Armstrong (1973) proposed that a belief of the form. This (perceived) object is ‘F’ is (non-inferential) knowledge if and only if the belief is a completely reliable sign that the perceived object is ‘F’, that is, the fact that the object is ‘F’ contributed to causing the belief and its doing so depended on properties of the believer such that the laws of nature dictated that, for any subject ‘x’ is to occur, and so thus a perceived object of ‘y’, if ‘x’ undergoing those properties is for ‘us’ to believe that ‘y’ is ‘F’, then ‘y’ is ‘F’. Dretske, (1981) offers a similar account, as to the belief’s being caused by a signal received by the perceiver that carries the information that the object is ‘F’.
This sort of condition fails, however, to be sufficient for non-inferential perceptual knowledge because it is compatible with the belief’s being unjustified, and an unjustifiable belief cannot be knowledge. For example, suppose that your mechanisms for colour perception are working well, but you have been given good reason to think otherwise, to think, say, that the substantive primary colours that are perceivable, that things look chartreuse to you and chartreuse things look magenta. If you fail to heed these reasons you have for thinking that your colour perception or sensory data is a directional way for us in believing of a thing that looks magenta, in that for you it is magenta, your belief will fail to be justified and will therefore fail to be knowledge, although the thing’s being magenta in such a way causes it as to be a completely reliable sign, or to carry the information, in that the thing is blush-coloured.
One could fend off this sort of counterexample by simply adding to the causal condition the requirement that the belief be justified, buy this enriched condition would still be insufficient. Suppose, for example, that in nearly all people, but not in you, as it happens, causes the aforementioned aberrations are colour perceptions. The experimenter tells you that you have taken such a drug but then says, ‘now wait, the pill you took was just a placebo’, suppose further, that this last thing the experimenter tells you is false. Her telling you that it was a false statement, and, again, telling you this gives you justification for believing of a thing that looks a subtractive primary colour to you that it is a sensorial primary colour, in that the fact you were to expect that the experimenters last statements were false, making it the case that your true belief is not knowledgeably correct, thought as though to satisfy its causal condition.
Goldman (1986) has proposed an importantly different causal criterion namely, that a true belief is knowledge, if it is produced by a type of process that is ‘globally’ and ‘locally’ reliable. Causing true beliefs is sufficiently high is globally reliable if its propensity. Local reliability deals with whether the process would have produced a similar but false belief in certain counterfactual situations alternative to the actual situation. This way of marking off true beliefs that are knowledge does not require the fact believed to be casually related to the belief, and so it could in principle apply to knowledge of any kind of truth.
Goldman requires that global reliability of the belief-producing process for the justification of a belief, he requires it also for knowledge because they require justification for knowledge, in what requires for knowledge but does not require for justification, which is locally reliable. His idea is that a justified true belief is knowledge if the type of process that produced it would not have produced it in any relevant counterfactual situation in which it is false. Noting that other concepts exhibit the same logical structure can motivate the relevant alternative account of knowledge. Two examples of this are the concept ‘flat’ and the concept ‘empty’ (Dretske, 1981). Both seem absolute concepts-a space is empty only if it does not contain anything and a surface is flat only if it does not have any bumps. However, the absolute character of these concepts is relative to a standard. For ‘flat’, there is a standard for what counts as a bump and for ‘empty’, there is a standard for what counts as a thing. To be flat is to be free of any relevant bumps and to be empty is to be devoid of all relevant things.
What makes an alternative situation relevant? Goldman does not try to formulate examples of what he takes to be relevantly alternate, but suggests of one. Suppose, that a parent takes a child’s temperature with a thermometer that the parent selected at random from several lying in the medicine cabinet. Only the particular thermometer chosen was in good working order, it correctly shows the child’s temperature to be normal, but if it had been abnormal then any of the other thermometers would have erroneously shown it to be normal. A globally reliable process has caused the parent’s actual true belief but, because it was ‘just luck’ that the parent happened to select a good thermometer, ‘we would not say that the parent knows that the child’s temperature is normal’. Goldman gives yet another example:
Suppose Sam spots Judy across the street and correctly believes
That it is Judy. If it did so occur that it was Judy’s twin sister,
Trudy, he would be mistaken her for Judy? Does Sam?
Know that it is Judy? As long as there is a serious possibility
That the person across the street might have been Trudy. Rather,
Than Judy. . . . We would deny that Sam knows.
(Goldman, 1986)
Goldman suggests that the reason for denying knowledge in the thermometer example, be that it was ‘just luck’ that the parent did not pick a non-working thermometer and in the twin’s example, the reason is that there was ‘a serious possibility’ that might have been that Sam could probably have mistaken for. This suggests the following criterion of relevance: An alternate situation, whereby, that the same belief is produced in the same way but is false, it is relevantly just in case at some point before the actual belief was to its cause, by which a chance that the actual belief was to have caused, in that the chance of that situation’s having come about was instead of the actual situation was too converged, nonetheless, by the chemical components that constitute its inter-actual exchange by which endorphin excitation was to influence and so give to the excitability of neuronal transmitters that deliver messages, inturn, the excited endorphins gave ‘change’ to ‘chance’, thus it was, in that what was interpreted by the sensory data and unduly persuaded by innate capabilities that at times are latently hidden within the mind, Or the brain, giving to its chosen chance of luck.
This avoids the sorts of counterexamples we gave for the causal criteria as we discussed earlier, but it is vulnerable to one or ones of a different sort. Suppose you were to stand on the mainland looking over the water at an island, on which are several structures that look (from at least some point of view) as would ne of an actualized point or station of position. You happen to be looking at one of any point, in fact a barn and your belief to that effect are justified, given how it looks to you and the fact that you have exclusively of no reason to think nor believe otherwise. Nevertheless, suppose that most the barn-looking structures on the island are not real barns but fakes. Finally, suppose that from any viewpoint on the mainland all of the island’s fake barns are obscured by trees and that circumstances made it very unlikely that you would have to a viewpoint not on the mainland. Here, it seems, your justified true belief that you are looking at a barn is not knowledge, although there was not a serious chance that there would have developed an alternative situation, wherefore you are similarly caused to have a false belief that you are looking at a barn.
That example shows that the ‘local reliability’ of the belief-producing process, on the ‘serous chance’ explication of what makes an alternative relevance, yet its view-point upon which we are in showing that non-locality is in addition to sustain of some probable course of the possibility for ‘us’ to believe in. Within the experience condition of application, the relationship with the sensory-data, as having a world-view that can encompass both the hidden and manifest aspects of nature would comprise of the mind, or brain that provides the excitation of neuronal ions, giving to sensory perception an accountable assessment of data and reason-sensitivity allowing a comprehensive world-view, integrating the various aspects of the universe into one magnificent whole, a whole in which we played an organic and central role. One-hundred years ago its question would have been by a Newtonian ‘clockwork universe’, a theoretical account of a probable ‘I’ universe that is completely mechanical. The laws of nature have predetermined everything that happens and by the state of the universe in the distant past. The freedom one feels regarding ones actions, even about the movement of one’s body, is an illusory infraction and the world-view expresses as the Newtonian one, is completely coherent.
Nevertheless, the human mind abhors a vacuum. When an explicit, coherent world-view is absent, it functions based on a tactic one. A tactic world-view is not subject to a critical evaluation, and it can easily harbour inconsistencies. Indeed, our tactic set of beliefs about the nature of reality consists of contradictory bits and pieces. The dominant component is a leftover from another period, the Newtonian ‘clock universe’ still lingers as we cling to this old and tired model because we know of nothing else that can take its place. Our condition is the condition of a culture that is in the throes of a paradigm shift. A major paradigm shift is complex and difficult because a paradigm holds ‘us captive: We see reality through it, as through coloured glasses, but we do not know that, we are convinced that we see reality as it is. Hence the appearance of a new and different paradigm is often incomprehensible. To someone raised believing that the Earth is flat, the suggestion that the Earth is spherically preposterous: If the Earth were spherical, would not the poor antipodes fall ‘down’ into the sky?
Yet, as we face a new millennium, we are forced to face this challenge. The fate of the planet is in question, and it was brought to its present precarious condition largely because of our trust in the Newtonian paradigm. As Newtonian world-view has to go, and, if one looks carefully, we can discern the main feature of the new, emergent paradigm. The search for these features is what was the influence of a fading paradigm. All paradigms include subterranean realms of tactic assumptions, the influence of which outlasts the adherence to the paradigm itself.
The first line of exploration suggests the ‘weird’ aspects of the quantum theory, with fertile grounds for our feeling of which should disappear in inconsistencies with the prevailing world-view. This feeling is in replacing by the new one, i.e., opinion or information assailing availability by means of ones parts of relating to the mind or spirit, which if in the event one believes that the Earth is flat, the story of Magellan’s travels is quite puzzling: How travelling due west is possible for a ship and, without changing direct. Arrive at its place of departure? Obviously, when the belief replaces the flat-Earth paradigm that Earth is spherical, we have instantly resolved the puzzle.
The founders of Relativity and quantum mechanics were deeply engaging but incomplete, in that none of them attempted to construct a philosophical system, however, that the mystery at the heart of the quantum theory called for a revolution in philosophical outlooks. During which time, the 1920's, when quantum mechanics reached maturity, began the construction of a full-blooded philosophical system that we based not only on science but on nonscientific modes of knowledge as well. As, the disappearing influences drawn upon the paradigm go well beyond its explicit claim. We believe, as the scenists and philosophers did, that when we wish to find out the truth about the universe, we can ignore nonscientific nodes of processing human experiences, poetry, literature, art, music are all wonderful, but, in relation to the quest for knowledge of the universe, they are irrelevant. Yet, it was Alfred North Whitehead who pointed out the fallacy of this speculative assumption. In this, within other aspects of thinking of some reality in which are the building blocks of reality are not material atoms but ‘throbs of experience’. Whitehead formulated his system in the late 1920s, and yet, as far as I know, the founders of quantum mechanics were unaware of it. It was not until 1963 that J.M. Burgers pointed out that its philosophy accounts very well for the main features of the quanta, especially the ‘weird ones’, enabling as in some aspects of reality is ‘higher’ or ’deeper’ than others, and if so, what is the structure of such hierarchical divisions? What of our place in the universe? Finally, what is the relationship between the great aspiration within the lost realms of nature? An attempt to endow ‘us’ with a cosmological meaning in such a universe seems totally absurd, and, yet, this very universe is just a paradigm, not the truth. When you reach its end, you may be willing to join the alternate view as accorded to which, surprisingly bestow ‘us’ with what we have restored, although in a post-postmodern context.
Subjective matter’s has regulated the philosophical implications of quantum mechanics, as to emphasis the connections between what I believe, in that investigations of such inter-connectivity are anticipatorially the hesitations that are an exclusion held within the western traditions, however, the philosophical thinking, from Plato to Platinous had in some aspects an interpretative cognitive process of presenting her in expression of a consensus of the physical community. Some have shared and by expressive objections to other aspects (sometimes vehemently) by others. Still other aspects express my own views and convictions, as turning about to be more difficult that anticipated, discovering that a conversational mode would be helpful, but, their conversations with each other and with me in hoping that all will be not only illuminating but finding to its read may approve in them, whose dreams are dreams among others than themselves.
These examples make it seem likely that, if there is a criterion for what makes an alternative situation relevant that will save Goldman’s claim about reliability and the acceptance of knowledge, it will not be simple.
The interesting thesis that counts asa causal theory of justification, in the meaning of ‘causal theory’ intend of the belief that is justified just in case it was produced by a type of process that is ‘globally’ reliable, that is, its propensity to produce true beliefs-that can be defined to some favourable approximations, as the proportion of the belief it produces, or would produce where it used as much as opportunity allows, that is true ~. Is sufficiently that a belief acquires favourable epistemic status by having some kind of reliable linkage to the truth? We have advanced variations of this view for both knowledge and justified belief. The first formulations of dependably an accounting measure of knowing came in the accompaniment of F.P. Ramsey 1903-30, who made important contributions to mathematical logic, probability theory, the philosophy of science and economics. Instead of saying that quarks have such-and-such properties, the Ramsey sentence says the theoretical are alternatively something that has those properties. If we have repeated the process for all of the theoretical terms, the sentence gives the ‘topic-neutral’ structure of the theory, but removes any implication that we know what the term so treated have as a meaning. It leaves open the possibility of identifying the theoretical item with whatever. It is that best fits the description provided, thus, substituting the term by a variable, Ramsey, was one of the first thinkers to accept a ‘redundancy theory of truth’, which he combined its radical views of the function of many kinds of the proposition. Neither generalizations, nor causal propositions, not those treating probabilities or ethics, described facts, but each has a different specific function in our intellectual commentators on the early works of Wittgenstein, and his continuing friendship with the latter liked to Wittgenstein’s return to Cambridge and to philosophy in 1929.
The most sustained and influential application of these ideas were in the philosophy of mind, or brain, as Ludwig Wittgenstein (1889-1951) whom Ramsey persuaded that remained work for him to do, the way of an undoubtedly charismatic figure of 20th-century philosophy, living and writing with a power and intensity that frequently overwhelmed his contemporaries and readers, being a kind of picture or model has centred the early period on the ‘picture theory of meaning’ according to which sentence represents a state of affairs of it. Containing elements corresponding to those of the state of affairs and structure or form that mirrors that a structure of the state of affairs that it represents. We have reduced to all logic complexity that of the ‘propositional calculus, and all propositions are ‘truth-functions of atomic or basic propositions.
In the layer period the emphasis shafts dramatically to the actions of people and the role linguistic activities play in their lives. Thus, whereas in the “Tractatus” language is placed in a static, formal relationship with the world, in the later work Wittgenstein emphasis its use through standardized social activities of ordering, advising, requesting, measuring, counting, excising concerns for each other, and so on. These different activities are thought of as so many ‘language games’ that together make or a form of life. Philosophy typically ignores this diversity, and in generalizing and abstracting distorts the real nature of its subject-matter. Besides the ‘Tractatus’ and the investigations, collections of Wittgenstein’s work published posthumously include ‘Remarks on the Foundations of Mathematics’ (1956), ‘Notebooks’ (1914-1916) ( 1961), ‘Pholosophische Bemerkungen’ (1964), ‘Zettel’ (1967), and ‘On Certainty’ (1969).
Clearly, there are many forms of reliabilism. Just as there are many forms of ‘foundationalism’ and ‘coherence’. How is reliabilism related to these other two theories of justification? We usually regard it as a rival, and this is aptly so, in as far as foundationalism and coherentism traditionally focussed on purely evidential relations than psychological processes, but we might also offer reliabilism as a deeper-level theory, subsuming some of the precepts of either foundationalism or coherentism. Foundationalism says that there are ‘basic’ beliefs, which acquire justification without dependence on inference, reliabilism might rationalize this indicating that reliable non-inferential processes have formed the basic beliefs. Coherence stresses the primary of systematicity in all doxastic decision-making. Reliabilism might rationalize this by pointing to increases in reliability that accrue from systematicity consequently, reliabilism could complement Foundationalism and coherence than completed with them.
These examples make it seem likely that, if there is a criterion for what makes an alternate situation relevant that will save Goldman’s claim about local reliability and knowledge. Will did not be simple. The interesting thesis that counts as a causal theory of justification, in the making of ‘causal theory’ intended for the belief as it is justified in case it was produced by a type of process that is ‘globally’ reliable, that is, its propensity to produce true beliefs that can be defined, to an acceptable approximation, as the proportion of the beliefs it produces, or would produce where it used as much as opportunity allows, that is true is sufficiently relializable. We have advanced variations of this view for both knowledge and justified belief, its first formulation of a reliability account of knowing appeared in the notation from F.P. Ramsey (1903-30). The theory of probability, he was the first to show how a ‘personalist theory’ could be developed, based on a precise behavioural notion of preference and expectation. In the philosophy of language. Much of Ramsey’s work was directed at saving classical mathematics from ‘intuitionism’, or what he called the ‘Bolshevik menace of Brouwer and Weyl. In the theory of probability he was the first to show how we could develop some personalists theory, as based on precise behavioural notation of preference and expectation. In the philosophy of language, Ramsey was one of the first thankers, which he combined with radical views of the function of many kinds of a proposition. Neither generalizations, nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy. Ramsey was one of the earliest commentators on the early work of Wittgenstein, and his continuing friendship that led to Wittgenstein’s return to Cambridge and to philosophy in 1929.
Ramsey’s sentence theory is the sentence generated by taking all the sentences affirmed in a scientific theory that use some term, e.g., ‘quark’. Replacing the term by a variable, and existentially quantifying into the result. Instead of saying that quarks have such-and-such properties, the Ramsey sentence says that there is something that has those properties. If we repeat the process for all of a group of the theoretical terms, the sentence gives the ‘topic-neutral’ structure of the theory, but removes any implication that we know what the term so treated prove competent. It leaves open the possibility of identifying the theoretical item with whatever, but it is that best fits the description provided. Virtually, all theories of knowledge. Of course, share an externalist component in requiring truth as a condition for known in. Reliabilism goes further, however, in trying to capture additional conditions for knowledge by ways of a nomic, counterfactual or other ‘external’ relations between belief and truth. Closely allied to the nomic sufficiency account of knowledge, primarily dur to Dretshe (1971, 1981), A.I. Goldman (1976, 1986) and R. Nozick (1981). The core of this approach is that x’s belief that ‘p’ qualifies as knowledge just in case ‘x’ believes ‘p’, because of reasons that would not obtain unless ‘p’ was true, or because of a process or method that would not yield belief in ‘p’ if ‘p’ were not true. An enemy example, ‘x’ would not have its current reasons for believing there is a telephone before it. Or would not come to believe this in the ways it does, thus, there is a counterfactual reliable guarantor of the belief’s bing true. Determined to and the facts of counterfactual approach say that ‘x’ knows that ‘p’ only if there is no ‘relevant alternative’ situation in which ‘p’ is false but ‘x’ would still believe that a proposition ‘p’; must be sufficient to eliminate all the alternatives to ‘p’ where an alternative to a proposition ‘p’ is a proposition incompatible with ‘p’? That in one’s justification or evidence for ‘p’ must be sufficient for one to know that every alternative to ‘p’ is false. This element of our evolving thinking, sceptical arguments have exploited about which knowledge. These arguments call our attentions to alternatives that our evidence sustains itself with no elimination. The sceptic inquires to how we know that we are not seeing a cleverly disguised mule. While we do have some evidence against the likelihood of such as deception, intuitively knowing that we are not so deceived is not strong enough for ‘us’. By pointing out alternate but hidden points of nature, in that we cannot eliminate, and others with more general application, as dreams, hallucinations, etc. The sceptic appears to show that every alternative is seldom. If ever, satisfied.
This conclusion conflicts with another strand in our thinking about knowledge, in that we know many things. Thus, there is a tension in our ordinary thinking about knowledge ~. We believe that knowledge is, in the sense indicated, an absolute concept and yet, we also believe that there are many instances of that concept.
If one finds absoluteness to be too central a component of our concept of knowledge to be relinquished, one could argue from the absolute character of knowledge to a sceptical conclusion (Unger, 1975). Most philosophers, however, have taken the other course, choosing to respond to the conflict by giving up, perhaps reluctantly, the absolute criterion. This latter response holds as sacrosanct our commonsense belief that we know many things (Pollock, 1979 and Chisholm, 1977). Each approach is subject to the criticism that it preserves one aspect of our ordinary thinking about knowledge at the expense of denying another. We can view the theory of relevant alternatives as an attempt to provide a more satisfactory response to this tension in our thinking about knowledge. It attempts to characterize knowledge in a way that preserves both our belief that knowledge is an absolute concept and our belief that we have knowledge.
Having to its recourse of knowledge, its cental questions include the origin of knowledge, the place of experience in generating knowledge, and the place of reason in doing so, the relationship between knowledge and certainty, and between knowledge and the impossibility of error, the possibility of universal scepticism, and the changing forms of knowledge that arise from new conceptualizations of the world. All these issues link with other central concerns of philosophy, such as the nature of truth and the natures of experience and meaning. Seeing epistemology is possible as dominated by two rival metaphors. One is that of a building or pyramid, built on foundations. In this conception it is the job of the philosopher to describe especially secure foundations, and to identify secure modes of construction, is that the resulting edifice can be shown to be sound. This metaphor of knowledge, and of a rationally defensible theory of confirmation and inference for construction, as that knowledge must be regarded as a structure risen upon secure, certain foundations. These are found in some formidable combinations of experience and reason, with different schools (empiricism, rationalism) emphasizing the role of one over that of the others. Foundationalism was associated with the ancient Stoics, and in the modern era with Descartes (1596-1650). Who discovered his foundations in the ‘clear and distinct’ ideas of reason? Its main opponent is coherentism, or the view that a body of propositions mas be known without a foundation in certainty, but by their interlocking strength, than as a crossword puzzle may be known to have been solved correctly even if each answer, taken individually, admits of uncertainty. Difficulties at this point led the logical passivists to abandon the notion of an epistemological foundation, and, overall, to philander with the coherence theory of truth. It is widely accepted that trying to make the connection between thought and experience through basic sentences depends on an untenable ‘myth of the given’.
Still, of the other metaphor, is that of a boat or fuselage, that has no foundation but owes its strength to the stability given by its interlocking parts. This rejects the idea of a basis in the ‘given’, favours ideas of coherence and holism, but finds it harder to ward off scepticism. In spite of these concerns, the problem, least of mention, is of defining knowledge about true beliefs plus some favoured relations between the believer and the facts that began with Plato’s view in the “Theaetetus” that knowledge is true belief, and some logos.` Due of its natural epistemology, the enterprising of studying the actual formation of knowledge by human beings, without aspiring to make evidently those processes as rational, or proof against ‘scepticism’ or even apt to yield the truth. Natural epistemology would therefore blend into the psychology of learning and the study of episodes I the history of science. The scope for ‘external’ or philosophical reflection of the kind that might result in scepticism or its refutation is markedly diminished. Although the term in a modern index has distinguished exponents of the approach include Aristotle, Hume, and J.S. Mills.
The task of the philosopher of a discipline would then be to reveal the correct method and to unmask counterfeits. Although this belief lay behind much positivist philosophy of science, few philosophers at present, subscribe to it. It places too well a confidence in the possibility of a purely a prior ‘first philosophy’, or standpoint beyond that of the working practitioners, from which they can measure their best efforts as good or bad. This point of view now seems that many philosophers are acquainted with the affordance of fantasy. The more modest of tasks that we actually adopt at various historical stages of investigation into different areas with the aim not so much of criticizing but more of systematization, in the presuppositions of a particular field at a particular tie. There is still a role for local methodological disputes within the community investigators of some phenomenon, with one approach charging that another is unsound or unscientific, but logic and philosophy will not, on the modern view, provide an independent arsenal of weapons for such battles, which indeed often come to seem more like political bids for ascendancy within a discipline.
This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge processed through some natural selection process, the best example of which is Darwin’s theory of biological natural selection. There is a widespread misconception that evolution proceeds according to some plan or direct, put it has neither, and the role of chance ensures that its future course will be unpredictable. Random variations in individual organisms create tiny differences in their Darwinian fitness. Some individuals have more offsprings than others, and the characteristics that increased their fitness thereby become more prevalent in future generations. Once upon a time, at least a mutation occurred in a human population in tropical Africa that changed the haemoglobin molecule in a way that provided resistance to malaria. This enormous advantage caused the new gene to spread, with the unfortunate consequence that sickle-cell anaemia came to exist.
In the modern theory of evolution, genetic mutations provide the blind variations (blind in the sense that variations are not influenced by the effects they would have -the likelihood of a mutation is not correlated with the benefits of liabilities that mutation would confer on the organism), the environment provides the filter of selection, and reproduction provides the retention, least of mention, the example of which Darwin’s theory of biological natural selection having three major components of the model of natural selection is the variation, selection and retention. All the same, it is to achieve because those organisms with features that make the no less adapted for survival do not survive in competition with other organisms in the environment that have features which are better adapted. Evolutionary epistemology applies this blind variation and selective retention model to the growth of scientific knowledge and to human thought processes in general.
The parallel between biological evolution and conceptual (or, epistemic) evolution can be seen in either literal or analogical. On this view, called the ‘evolution of cognitive mechanisms’ program’ (EEM) by Bradie (1986) and te ‘Darwinian approach into epistemology’ by Ruse (1986), the growth of knowledge occurs through blind variation and selective retention because biological natural selection itself is the cause of epistemic variation and selection. The most plausible version of the literal view does not hold that all human beliefs are innate than that of the mental mechanisms which guide the acquisition of non-innate beliefs ae themselves innate and result of biological natural selection. Ruse (1986) defends a version of literal evolution which her links to sociology. (Bradie and Rescher, 1990)
On the analogical version of evolutionary epistemology called, the ‘evolutions of theories program’ (EET) by Bradie (1986) and the ‘Spencerian approach (after the nineteenth-century philosopher Herbert Spencer) by Ruse (1986), the development of human knowledge is governed by a process analogous to biological natural selection, than by an instance of the mechanism itself. This version of evolutionary epistemology, introduced and elaborated by Donald Campbell (1947) and a mental process of trial and error known as epistemic natural selection.
Both versions of evolutionary epistemology are usually taken to be types on naturalized epistemology, because both take some empirical facts as a starting point for their epistemological project. The literal version of rhetorical epistemology begins by accepting evolutionary theory and a materialist approach to the mind and, from these, constructs an account of knowledge and its development. In contrast, the analogical version does not require the truth of biological evolution, it simply draws on biological evolution as a source for the model of natural selection. Consequently of evolutionary epistemology to be true, the model of natural selection need only apply to the growth of knowledge, not to the origin and development of species. Crudely put, evolutionary epistemology and the analogical sort could still be true if creationism is the correct theory of the origin of species.
Although they do not begin by assuming evolutionary theory, most analogical evolutionary epistemologists are naturalized epistemologists as well, for which their empirical assumptions come from psychology and cognitive science, not evolutionary theories. Sometimes, however, evolutionary epistemology is characterized in a seeming non-naturalistic fashion. Campbell (1974) says that ‘if one is expanding knowledge beyond what one knows, one has no choice but to explore without the benefit of wisdom’ (i.e., blindly). This, Campbell admits, makes evolutionary epistemology close to being a tautology (and so non-naturalistic). Evolutionary epistemology does assert the analytic claim that when expanding one’s knowledge beyond what one knows, one must proceed with something that is not already known, but, more interestingly, it also makes the synthetic claim that when expanding one’s knowledge beyond what one knows, one must proceed by blind variation and selective retention. This claim is synthetic because it can be empirically falsified. The central claim of evolutionary epistemology is synthetic, not analytic. If the central claim were analytic, then all non-evolutionary epistemology would be logically contradictory, which they are not.
With respect to progress, the problem is that biological evolution is not goal-directed, but the growth of human knowledge may be. Campbell (1974) worries about the potential disanalogy, but is willing to bite the bullet and admit that epistemic evolution progress toward a goal (truth) while biological evolution does not. Some have argued that evolutionary epistemology must give up the ‘truth-tropic’ sense of progress because a natural selection model is in essence, non-teleological, where instead, following Kuhn (1970), an operational sense of progress can be embraced along with evolutionary epistemology.
Many evolutionary epistemologists try to combine the literal and the analogical version, saying that those beliefs and cognitive mechanisms which are innate result from natural selection of the biological sort and those which are in absence of innate results from natural selection of the epistemic sort. This is reasonable since the two parts of this hybrid view are kept distinct. An analogical version evolutionary epistemology with biological variation as its only source of blindness would be a null theory: This would be the case if all our beliefs are innate or if our non-innate beliefs are not the result of blind variation. An appeal to the blindness of biological variation is thus not a legitimate way to produce a hybrid version of evolutionary epistemology since doing so trivializes the theory. For similar reasons, such an appeal will not save an analogical version of evolutionary epistemology from arguments to the effect that epistemic variation is not blind (Stein and Lipton, 1990).
Chance can influence the outcome at each result: First, in the creation of genetic mutation, second, in wether the bearer lives long enough to show its effects, thirdly, in chance events that influence the individual’s actual reproductive success, and fourth, in wether a gene even if favoured in one generation, is, happenstance, eliminated in the next, and finally in the many unpredictable environmental changes that will undoubtedly occur in the history of any group of organisms. As Harvard biologist Stephen Jay Gould has so vividly expressed that process again, the outcome would surely be different. Not only might there not be humans, there might not even be anything like mammals.
We will often emphasis the elegance of traits shaped by natural selection, but the common idea that nature creates perfection needs to be analysed carefully. The extent to which evolution achieves perfection depends on exactly what you mean. If you mean “Does natural selections always take the best path for the long-term welfare of a species?” The answer is no. That would require adaption by group selection, and this is, unlikely. If you mean “Does natural selection creates every adaption that would be valuable?” The answer again, is no. For instance, some kinds of South American monkeys can grasp branches with their tails. The trick would surely also be useful to some African species, but, simply because of bad luck, none have it. Some combination of circumstances started some ancestral South American monkeys using their tails in ways that ultimately led to an ability to grab onto branches, while no such development took place in Africa. Mere usefulness of a trait does not necessitate it mean that will evolve.
This is an approach to the theory of knowledge that sees an important connection between the growth of knowledge and biological evolution. An evolutionary epistemologist claims that the development of human knowledge proceeds through some natural selection process, the best example of which is Darwin’s theory of biological natural selection. The three major components of the model of natural selection are variation selection and retention. According to Darwin’s theory of natural selection, variations are not pre-designed to perform certain functions. Rather, these variations that perform useful functions are selected. While those, which do not, are not selected as such a selection is responsible for the appearing variations that intentionally occur. In the modern theory of evolution, genetic mutations provide the blind variations (blind in the sense that variations are not influenced by the effects they would have the likelihood of a mutation is not correlated with the benefits or liabilities that mutation would confer on the organism), the environment provides the filter of selection, and reproduction provides the retention. Correspondingly, it is achieved because those organisms with features that make them less adapted for survival do not survive concerning other organisms in the environment that have features that are better adapted. Evolutionary epistemology applies this blind variation and selective retention model to the growth of scientific knowledge and to human thought processes in general.
The parallel between biological evolution and conceptual or we can see ‘epistemic’ evolution as either literal or analogical. The literal version of evolutionary epistemology dees biological evolution as the main cause of the growth of knowledge. On this view, called the ‘evolution of cognitive mechanic programs’, by Bradie (1986) and the ‘Darwinian approach to epistemology’ by Ruse (1986), that growth of knowledge occurs through blind variation and selective retention because biological natural selection itself is the cause of epistemic variation and selection. The most plausible version of the literal view does not hold that all human beliefs are innate but rather than the mental mechanisms which guide the acquisition of non-innate beliefs are themselves innately and the result of biological natural selection. Ruses (1986) made-up tranquillity, demands of an interlingual rendition of literal evolutionary epistemology that he links to sociology (Rescher, 1990).
On the analogical version of evolutionary epistemology, called the ‘evolution of theory’s program’, by Bradie (1986). The ‘Spenserians approach’ (after the nineteenth century philosopher Herbert Spencer) by Ruse (1986), a process analogous to biological natural selection has governed the development of human knowledge, rather than by an instance of the mechanism itself. This version of evolutionary epistemology, introduced and elaborated by Donald Campbell (1974) and Karl Popper, sees the [partial] fit between theories and the world as explained by a mental process of trial and error known as epistemic natural selection.
We have usually taken both versions of evolutionary epistemology to be types of naturalized epistemology, because both take some empirical facts as a starting point for their epistemological project. The literal version of evolutionary epistemology begins by accepting evolutionary theory and a materialist approach to the mind and, from these, constructs an account of knowledge and its developments. By contrast, the analogical, the version does not require the truth of biological evolution: It simply draws on biological evolution as a source for the model of natural selection. For this version of evolutionary epistemology to be true, the model of natural selection need only apply to the growth of knowledge, not to the origin and development of species. Crudely put, evolutionary epistemology of the analogical sort could still be true even if creationism is the correct theory of the origin of species.
Although they do not begin by assuming evolutionary theory, most analogical evolutionary epistemologists are naturalized epistemologists as well, their empirical assumptions, least of mention, implicitly come from psychology and cognitive science, not evolutionary theory. Sometimes, however, evolutionary epistemology is characterized in a seemingly non-naturalistic fashion. (Campbell 1974) says that ‘if one is expanding knowledge beyond what one knows, one has no choice but to explore without the benefit of wisdom’, i.e., blindly. This, Campbell admits, makes evolutionary epistemology close to being a tautology (and so not naturalistic). Evolutionary epistemology does assert the analytic claim that when expanding one’s knowledge beyond what one knows, one must precessed to something that is already known, but, more interestingly, it also makes the synthetic claim that when expanding one’s knowledge beyond what one knows, one must proceed by blind variation and selective retention. This claim is synthetic because we can empirically falsify it. The central claim of evolutionary epistemology is synthetic, not analytic. If the central contradictory, which they are not. Campbell is right that evolutionary epistemology does have the analytic feature he mentions, but he is wrong to think that this is a distinguishing feature, since any plausible epistemology has the same analytic feature (Skagestad, 1978).
Two extra-ordinary issues lie to awaken the literature that involves questions about ‘realism’, i.e., What metaphysical commitment does an evolutionary epistemologist have to make? (Progress, i.e., according to evolutionary epistemology, does knowledge develop toward a goal?) With respect to realism, many evolutionary epistemologists endorse that is called ‘hypothetical realism’, a view that combines a version of epistemological ‘scepticism’ and tentative acceptance of metaphysical realism. With respect to progress, the problem is that biological evolution is not goal-directed, but the growth of human knowledge is. Campbell (1974) worries about the potential dis-analogy here but is willing to bite the stone of conscience and admit that epistemic evolution progress toward a goal (truth) while biological evolution does not. Some have argued that evolutionary epistemologists must give up the ‘truth-topic’ sense of progress because a natural selection model is in accepting assumption from non-teleological, instead, following Kuhn (1970), an embrace along with evolutionary epistemology.
Among the most frequent and serious criticisms levelled against evolutionary epistemology is that the analogical version of the view is false because epistemic variation is not blind (Skagestad, 1978 and Ruse, 1986), Stein and Lipton (1990) have argued, however, that this objection fails because, while epistemic variation is not random, its constraints come from heuristics which, for the most part, are selective retention. Further, Stein and Lipton argue that lunatics are analogous to biological pre-adaptions, evolutionary pre-biological pre-adaptions, evolutionary cursors, such as a half-wing, a precursor to a wing, which have some function other than the function of their descendable structures: The function of descentable structures, the function of their descendable character embodied to its structural foundations, is that of the guidelines of epistemic variation is, on this view, not the source of disanalogy, but the source of a more articulated account of the analogy.
Many evolutionary epistemologists try to combine the literal and the analogical versions (Bradie, 1986, and Stein and Lipton, 1990), saying that those beliefs and cognitive mechanisms, which are innate results from natural selection of the biological sort and those which are innate results from natural selection of the epistemic sort. This is reasonable asa long as the two parts of this hybrid view are kept distinct. An analogical version of evolutionary epistemology with biological variation as its only source of blondeness would be a null theory: This would be the case if all our beliefs are innate or if our non-innate beliefs are not the result of blind variation. An appeal to the legitimate way to produce a hybrid version of evolutionary epistemology since doing so trivializes the theory. For similar reasons, such an appeal will not save an analogical version of evolutionary epistemology from arguments to the effect that epistemic variation is blind (Stein and Lipton, 1990).
Although it is a relatively new approach to theory of knowledge, evolutionary epistemology has attracted mush attention, primarily because it represents a serious attempt to flesh out a naturalized epistemology by drawing on several disciplines. If science is used for understanding the nature and development of knowledge, then evolutionary theory is among the disciplines worth a look. Insofar as evolutionary epistemology looks there, it is an interesting and potentially fruitful epistemological programme.
What makes a belief justified and what makes a true belief knowledge? It is natural to think that whether a belief deserves one of these appraisals, but depends on what induced or had given cause for any subject that has the belief. In recent decades several epistemologists have pursued this plausible idea with a variety of specific proposals. Some causal theories of knowledge have it that a true belief that ‘p’ is knowledge just in case it has the right sort of causal connection to the fact that ‘p’. They can apply such a criterion only to cases where the fact that ‘p’ is a sort that can enter inti causal relations, as this seems to exclude mathematically and other necessary facts and perhaps any fact expressed by a universal generalization, and proponents of this sort of criterion have usually supposed that it is limited to perceptual representations where knowledge of particular facts about subjects’ environments.
For example, Armstrong (1973) proposed that a belief of the form ‘This [perceived] object is ‘F’ is [non-inferential] knowledge if and only if the belief is a completely reliable sign that the perceived object is ‘F’, that ism, the fact that the object is ‘F’ contributed to causing the belief and its doing so depended on properties of the believer such that the laws of nature dictated that, for any subject ‘χ’ and perceived object ‘y’, if ‘χ’ has those properties and believed that ‘y’ is ‘F’, then ‘y’ is ‘F’. (Dretske (1981) offers a rather similar account, as the belief’s being caused by a signal received by the perceiver that carries the information that the object is ‘F’).
This sort of condition fails, however, to be sufficiently for non-inferential perceptivity, for knowledge is accountable for its compatibility with the belief’s being unjustified, and an unjustified belief cannot be knowledge. For example, suppose that your organism for sensory data of colour as perceived, is working well, but you have been given good reason to think otherwise, to think, say, that the sensory data of things look chartreuse to say, that chartreuse things look magenta, if you fail to heed these reasons you have for thinking that your colour perception is awry and believe of a thing that looks magenta to you that it is magenta, your belief will fail top be justified and will therefore fail to be knowledge, although it is caused by the thing’s being withing the grasp of sensory perceptivity, in a way that is a completely reliable sign, or to carry the information that the thing is sufficiently to organize all sensory data as perceived in and of the World, or Holistic view.
The view that a belief acquires favourable epistemic status by having some kind of reliable linkage to the truth. Variations of this view have been advanced for both knowledge and justified belief. The first formulation of a reliable account of knowing notably appeared as marked and noted and accredited to F. P. Ramsey (1903-30), whereby much of Ramsey’s work was directed at saving classical mathematics from ‘intuitionism’, or what he called the ‘Bolshevik menace of Brouwer and Weyl’. In the theory of probability he was the first to develop, based on precise behavioural nations of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a ‘redundancy theory of truth’, which he combined with radical views of the function of many kinds of propositions. Neither generalizations, nor causal positions, nor those treating probability or ethics, described facts, but each has a different specific function in our intellectual economy. Ramsey was one of the earliest commentators on the early work of Wittgenstein, and his continuing friendship with the latter to Wittgenstein’s return to Cambridge and to philosophy in 1929. Additionally, Ramsey, who said that an impression of belief was knowledge if it were true, certain and obtained by a reliable process. P. Unger (1968) suggested that ‘S’ knows that ‘p’ just in case it is of at all accidental that ‘S’ is right about its being the case that D.M. Armstrong (1973) drew an analogy between a thermometer that reliably indicates the temperature and a belief interaction of reliability that indicates the truth. Armstrong said that a non-inferential belief qualified as knowledge if the belief has properties that are nominally sufficient for its truth, i.e., guarantee its truth via laws of nature.
Closely allied to the nomic sufficiency account of knowledge, primarily due to F.I. Dretske (1971, 1981), A.I. Goldman (1976, 1986) and R. Nozick (1981). The core of this approach is that ‘S’s’ belief that ‘p’ qualifies as knowledge just in case ‘S’ believes ‘p’ because of reasons that would not obtain unless ‘p’s’ being true, or because of a process or method that would not yield belief in ‘p’ if ‘p’ were not true. For example, ‘S’ would not have his current reasons for believing there is a telephone before him, or would not come to believe this in the way he does, unless there was a telephone before him. Thus, there is a counterfactual reliable guarantor of the belief’s being true. A variant of the counterfactual approach says that ‘S’ knows that ‘p’ only if there is no ‘relevant alternative’ situation in which ‘p’ is false but ‘S’ would still believe that ‘p’ must be sufficient to eliminate all the other situational alternatives of ‘p’, where an alternative to a proposition ‘p’ is a proposition incompatible with ‘p’, that is, one’s justified evidence for ‘p’ must be sufficient for one to know that every subsidiary situation is ‘p’ is false.
They standardly classify reliabilism as an ‘externaturalist’ theory because it invokes some truth-linked factor, and truth is ‘eternal’ to the believer the main argument for externalism derives from the philosophy of language, more specifically, from the various phenomena pertaining to natural kind terms, indexicals, etc., that motivate the views that have become known as direct reference’ theories. Such phenomena seem, at least to show that the belief or thought content that can be properly attributed to a person is dependent on facts about his environment ~, e.g., whether he is on Earth or Twin Earth, what in fact he is pointing at, the classificatory criteria employed by the experts in his social group, etc. Not just on what is going on internally in his mind or brain (Burge, 1979.) Nearly all theories of knowledge, of course, share an externalist component in requiring truth as a condition for knowing. Reliabilism goes further, however, in trying to capture additional conditions for knowledge by means of a nomic, counterfactual or other ‘external’ relations between ‘belief’ and ‘truth’.
The most influential counterexample to reliabilism is the demon-world and the clairvoyance examples. The demon-world example challenges the necessity of the reliability requirement, in that a possible world in which an evil demon creates deceptive visual experience, the process of vision is not reliable. Still, the visually formed beliefs in this world are intuitively justified. The clairvoyance example challenges the sufficiency of reliability. Suppose a cognitive agent possesses a reliable clairvoyance power, but has no evidence for or against his possessing such a power. Intuitively, his clairvoyantly formed beliefs are unjustifiably unreasoned, but reliabilism declares them justified.
Another form of reliabilism, ‘normal worlds’, reliabilism (Goldman, 1986), answers the range problem differently, and treats the demon-world problem in the same stroke. Let a ‘normal world’ be one that is consistent with our general beliefs about the actual world. Normal-worlds reliabilism says that a belief, in any possible world is justified just in case its generating processes have high truth ratios in normal worlds. This resolves the demon-world problem because the relevant truth ratio of the visual process is not its truth ratio in the demon world itself, but its ratio in normal worlds. Since this ratio is presumably high, visually formed beliefs in the demon world turn out to be justified.
Yet, a different version of reliabilism attempts to meet the demon-world and clairvoyance problems without recourse to the questionable notion of ‘normal worlds’. Consider Sosa’s (1992) suggestion that justified beliefs is belief acquired through ‘intellectual virtues’, and not through intellectual ‘vices’, whereby virtues are reliable cognitive faculties or processes. The task is to explain how epistemic evaluators have used the notion of indelible virtues, and vices, to arrive at their judgements, especially in the problematic cases. Goldman (1992) proposes a two-stage reconstruction of an evaluator’s activity. The first stage is reliability, based acquisition of a ‘list’ of virtues and vices. The second stage is application of this list to queried cases. Determining has executed the second stage whether processes in the queried cases resemble virtues or vices. We have classified visual beliefs in the demon world as justified because visual belief formation is a virtue. Clairvoyance formed, beliefs are classified as unjustified because clairvoyance resembles scientifically suspect processes that the evaluator represents as vices, e.g., mental telepathy, ESP, and so forth.
Clearly, there are many forms of reliabilism, just as there are many forms of foundationalism and coherentism. How is reliabilism related to these other two theories of justification? They have usually regarded it as a rival, and this is apt in as far as foundationalism and coherentism traditionally focussed on purely evidential relations rather than psychological processes. But reliabilism might also to be offered as a deeper-level theory, subsuming some precepts of either foundationalism or coherentism. Foundationalism says that there are ‘basic’ beliefs, which acquire justification without dependency on inference. Reliabilism might rationalize this by indicating that reliable non-inferential processes form the basic beliefs. Coherentism stresses the primary of systematicity in all doxastic decision-making. Reliabilism might rationalize this by pointing to increases in reliability that accrue from systematicity. Thus, reliabilism could complement foundationalism and coherentism than complete with them.
Philosophers often debate the existence of different kinds of tings: Nominalists question the reality of abstract objects like class, numbers, and universals, some positivist doubt the existence of theoretical entities like neutrons or genes, and there are debates over whether there are sense-data, events and so on. Some philosophers may be happy to talk about abstract one, if it is contained to theoretic entities, while denying that they really exist. This requires a ‘metaphysical’ concept of ‘real existence’: We debate whether numbers, neutrons and sense-data really existing things. But it is difficult to see what this concept involves and the rules to be employed in setting such debates are very unclear.
Questions of existence seem always to involve general kinds of things, do numbers, sense-data or neutrons exit? Some philosophers conclude that existence is not a property of individual things, ‘exists’ is not an ordinary predicate. If I refer to something, and then predicate existence of it, my utterance is tautological, the object must exist for me to be able to refer to it, so predicating for me to be able to refer to it, so predicating existence of it adds nothing. And to say of something that it did not exist would be contradictory.
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